Blender Render (Internal) How to control smoke direction? I am trying to create a smokey "afterburner" on a spaceship. How do you control the density direction to simulate different environments? In this case, I want to simulate space (zero density?), where "smoke/fire" looking effects should not go upward, but should disperse evenly in the emitter direction.

You can see in the picture when the emitter changes direction, the smoke does not change direction as you would expect in space.

I tried:

Turning down density on both smoke emitter (flow) and box (domain)

Smoke still goes straight up

Using particle system

The particles move in the desired direction, but the smoke always floats up

I would use a wind forcefield with a strength of about 7. Make sure it's pointed in the same direction that you want your smoke to blow in. Keep it a little bit away from the domain, or else smoke would flow around it and it would look weird.


Shared preferences/addons across different machines (e.g. Dropbox) how do you guys keep your settings when switching computers (e.g. home/work)?

I'm still in the process of finding my perfect setup, and I would like to have all the changes that I make and all the addons I install available on all machines that I work on.

Do you just link your 2.75 folder to a dropbox folder to keep everything synced? That would even sync unwanted stuff like recent projects and bookmarks. And the filepaths are stored there as well which are not the same on every machine/OS.

It seems like this thread should help. Copying startup.blend (this contains your startup scene) and userpref.blend (this contains your user preferences) to Dropbox and syncing them should have the result you're after. You would have to manually copy and paste the files to and from the Dropbox folder on each machine each time you changed them, however, so it won't be an automatic update.

ex. Working at home, make changes to User Preferences, copy userpref.blend to Dropbox, go to work, move userpref.blend from Dropbox to Blender folder. You would also have to do the same with the addons you installed.


Analog gauges in BGE How would I make analog gauges (like fuel, RPM, etc.) in the BGE?
I have tried using orientation constraints but it did not work.

well you could use like a python script.
set the origin point of the needle to its bottom and.

why not something like this tied to an always actuator?

    import bge
    from bge import logic
    from math import degrees

    cont = logic.getCurrentController()
    own = cont.owner
    own_rotation = own.worldOrientation.to_euler()
    POINT=own["AMOUNT"]
    MAXPOINT=1
    MINPOINT=0
    if ( POINT < MAXPOINT) & ( POINT > MINPOINT):
        own.worldOrientation = (0,0,POINT)
    elif POINT > MAXPOINT:
        own.worldOrientation = (0,0,MAXPOINT)
    elif POINT < MINPOINT:
        own.worldOrientation = (0,0,MINPOINT)

it should set the rotation every time a value changes. you can change the Amount property every time you want the meter to go up or down, and the meter will follow it.
NOTE: this takes in RADIANS not DEGREES! and Sets it in RADIANS!


Keying set failed to insert any keyframes When pressing I, I now receive:

  keying set failed to insert any keyframes.

No idea why pressing I doesn't work anymore. What did I do wrong?
(I've upgraded from 2.71 to 2.72 and it stops working).

See screenshot: The solution was to remove the keying set at the bottom and when selecting the camera, to remove the 2 keying sets that were there.

I however have no idea how this was enabled, and at this point of time I also don't know the goal of this keying.

After removal, the I key worked again.


Blender's "View Animation Ctrl F11" shows purple (missing image) background instead of transparency in 2.83 / 2.90 The title almost says it all. In previous Blender versions, when I rendered images with transparent background and saved them as PNG sequence, I could play the animation in Blender with "View Animation" (Ctrl+F11) and the animation had a transparent background.
Now in Blender 2.83 LTS (and I checked a 2.90 test build as well), the background is no longer shown as transparent, but purple like there is a missing texture or image. And it doesn't matter if I used an HDRI as background or just the default grey color. The player always shows the animation with a purple background. I tried switching from PNG to TIF and EXR, all the files are rendered and saved correctly with transparency - but the internal blender player seems to be unable to show transparency. Using an older 2.79 version playing the same image sequence shows correct transparency. Is there a setting I can't find to change it back to how it was before?
Thanks for your help.

This might be a bug. In the latest build this doesn't happen anymore.


Rotate text with curve modifier without spiraling I'm working through this watch creation tutorial, and I have text with a curve modifier added to it, using a bezier circle as the targeted object.  The problem I'm having is that when I attempt to rotate the numbers into correct position, regardless of whether I rotate either the bezier circle or the text object, the text begins to spiral.  Is there a way to rotate without the spiral happening?

The transformation axis in the screenshot is X.
If you rotate your text, the X values of the text are different and it spirals.

Solution:
Translate the text only on the X axis (G-key followed by X-key). This way the text moves along the circle.


Export a .obj to .mesh format for Ogre I have an .obj I want to export as a .mesh to use in Ogre3D, but I can't find how to do it. I downloaded an addon to add an option for OGRE Exporter, but the final file doesn't work with Ogre. It's a .mesh.xml and I need a .mesh only. Of course renaming the file extension doesn't work.

You need to use the OgreXML converter tool.
Converts the xml to binary .mesh file.
Some of the exporters will convert it in the background for you if you set up the exporter correctly. You can also do this manually.
See the wiki below for information about the converter.

http://www.ogre3d.org/tikiwiki/OgreXmlConverter


Retain circular shape after adding subdivisions with sub surf mod applied Anytime you need to add additional subdivisions to only certain edges of a circle (not all edges) you wind up with a shape that's no longer circular when the sub surf mod calculates the curve between the newly added vertex and the original vertices.

Logically it seems that there should be a way to determine where that new vertex needs to be to make the resulting sub surf line appear circular. Unfortunately,  as a human, it's hard for me to pinpoint that exact location by eye.

Is there a tool or command that re-circularizes the shape once I add my subdivision to my circles edge? Am I thinking about this the wrong way such that there's an alternative path that fixes the problem without this tool?

Thanks in adv.

If I understand well, your issue is to recalculate edges/vertices to be circle shape after adding more cuts, maybe this answer could help.
Anyway if that the case, you should first outline well your circle mesh using as less as possible edges, or add circle mesh instead outlining it by hand.


Blender 2.81a crashes while trying to render 2.8 file with Radeon ProRender I had a Nvidia GT 1030 graphics card 2 Months Ago. Back at that time I followed a BlenderGuru tutorial to make a donut. I could render it perfectly. Let's just call that file Donut.blend

https://drive.google.com/open?id=1EcyqoXdAokoTObYmUztQa9PLKH__h3t6 Here You can get my test files including donut.blend (Note:- cube.blend at this link was created using 2.81a)

But then I switched to a Radeon RX580 which I can use to render with Radeon ProRender but only with newly created 2.81 Blender files.

I also collected the sample from this thread. The blend file attached https://community.amd.com/thread/240919 here also works, using 2.81a (current version). Even if the fact is that it was a 2.8 file.

But the donut that I made 5 months ago using blender 2.8, doesn't render using Radeon Pro Render.

CPU (i3-4150) + Cycles works fine for Donut.blend on both Blender 2.8
and 2.81a
RX580 Gpu + Cycles doesn't work for Donut.blend on whatever blender
version I use. (Checked way back till 2.79.)
RX580 + Radeon Pro Render doesn't work for Donut.blend (tested on
2.81a, 2.81, 2.81 beta, 2.8, 2.8 beta)

(Donut.blend won't run on 2.79 as it was created using 2.8)

CPU + Radeon Pro Render doesn't work for Donut.blend (tested on
2.81a, 2.81, 2.81 beta, 2.8, 2.8 beta).
CPU + RX580 + Radeon Pro Render also doesn't work.

But If I create any new file with 2.81a in Blender then Radeon Pro Render works also for that 2.8 created file at that thread. But my 2.8 Donut.blend crashes and shuts down without any message or error message!

I have attached a 2.81a created render (cube.png) which was rendered using Radeon Pro Render.

The problem is with ProRender. I used Color Ramp with displacement node, that caused the problem while rendering at ProRender version 2.2 for Blender.
They partly fixed the issue, but for some particular cases it will still crash, but they are tryng to fix it.


What is happening here? Boolean modifier works *almost* So I want to hollow out a spheroid.
I redo the normals, extrude inwards, use p to separate the smaller spheroid copy, extrude its faces only outwards, move it into another layer, then use a boolean to subtract this from the original (big) spheroid. You see the result. It works almost.

Why not completely? What am I doing wrong? The smaller sphere's protrusions definitely go fully beyond the bigger sphere on both sides, inside and outside.

Here is the file for download: http://www.pasteall.org/blend/41696

You can do this with the new (blender 2.76+) intersect (boolean) feature.

Steps to recreate:

Go to edit mode (Tab).
Select all (A).
Extrude inwards (E).
Go to Face select mode (CtrlTab).
Extrude individual (Tools panel-->Add-->Extrude Individual) outwards.
Select entire inner mesh island (CtrlL).
Open dynamic spacebar menu (Space).
Type in "Intersect (Boolean)" and confirm.


Animating a fluid water fountain I was trying to make a water fountain and animate water flowing through it. I added the domain and inflow to the mesh but couldn't make the water flow out of the mesh/fountain. It just drops straight down from the mesh. I want to make a real life water fountain where water first comes out/up from the bottom/inside to a certain height then take up a certain area and finally fall back down.

I guess what I'm trying to say is control the direction and area of flow of the fluid. If you guys have any idea how to achieve that, any help would be appreciated. Thanks in advance.

You need to set the inflow's velocity to be positive in the Z direction. This will force the inflow's fluid up, giving you the fountain effect. Here is a bit about an example I quickly put together.

(click on the images to see a larger version)

Inflow settings (just a simple cube):

Domain settings:

Outflow plane below the fountain to "kill" all water than falls below. This is like a vacuum to "suck up" the water.

The fountain model itself is just a simple fluid obstacle.


How to achieve inward folding after extrude as shown on the right side of the picture

I would go around it as to make it while Extrude you will need to place 3D Cursor in right place and Scale extrusion to it.

You can instead make it as such:

Add Solidify modifier with Even Thickness.
Apply it.
Go to Edit Mode.
Select needed faces.
I to Inset.
Delete created faces.


Why do the workspace tabs disappear when I switch to another tab from Layout? Starting sometime after blender-2.80.0-git.855b3e68ef27-windows64 - when I start Blender 2.8 I get the usual workspace tabs interface but when I switch from layout to some workspaces (UV Editing, Texture Paint, Shading, Rendering, Compositing, Scripting, Masking, Motion Tracking, Video Editing) the tabs disappear.
Modeling, Sculpting, Animation, Layout all retain the tabs.

I just downloaded blender-2.80.0-git.8df5e0eb66f7-windows64 today - still have the issue.

How do I fix this?

The problem is interface scaling. On my 4k monitor I had set the scale to 1.5. If I drop the scaling to 1.4 all the tabs are there for every workspace. Around 1.42 some workspaces have no tabs.

The 2/19/19 build (blender-2.80.0-git.855b3e68ef27-windows64) did not have the problem at 1.5 scale.

FYI


How do I make the feathers on a bird wing bend with physics? I've seen videos of people doing it so I know it's possible, but I don't want to use bones on every single feather. I've searched around and experimented for hours now and I just can't figure it out. I've tried soft bodies and cloth physics but that doesn't seem to work with feathers. I want it to obey physics as well. If I animate the wing flapping down the feathers should curve back and vice versa, and of course the feather has to stay attached to the limb. I hope this makes sense.

blender physics likes simple shapes, you can get around this by using mesh deform modifiers, and surrounding the mesh you want to deform with a simple shape.  For a feather, something like a 4 segmented rectangle around each feather.  Then apply soft body or cloth physics to the rectangle.


Python: deselect outliner elements How can I deselect Text in the outliner? bpy.ops.object.select_all(action='DESELECT') will not work for this. I can just click with the mouse on Plane in the outliner and it works, but I want to do this in Python and didn't find a way yet.

That highlight is indicating the current active object.
I was about to tell you that you can't really do that, since most of that data is read-only, but after some stubborn, extra googling, it turns out you actually can!
bpy.context.view_layer.objects.active = None

I guess we both learned something new today.


Black patches in lowpoly mesh I wonder what is the reason that causes the black patches in the result using cycles renderer with smooth shading? Is there any other way to fix them without making more subdivisions (The black blotches disappear when I use 2x subdivision surface)?

Blender file:

There is an option to get rid of those shadows by smoothing the mesh. Reason of those shadows is hard angle between faces.
Main downside of it is loosing some details along the mesh, but you can try and smooth only needed "patches".
In my example I've smoothed whole mesh by Smooth Vertex 5 times.

You can also Subdivide Smooth selected faces, but this will generate tris/ngons around selection.


Texture-painted images turn black when used? I was experimenting with texture painting and noticed something really, really annoying.

I spent 15-30 minutes painting, saved, then used the map as a texture. Note that I saved immediately after painting and before setting the object texture.

As soon as I did, it turned black. I couldn't make it go back, so I quit, making sure to not to save the messed up image. When I opened the save, the map was still messed up.

Does it automatically save changes to the UV even when the blend it's self isn't saved?

i had this problem ... you just open a new tab and open the uv/image editor , in your 3d view go into edit mode for the object you want ( which is black ) , and then in the uv/image editor , click the texture panel and select the texture you want .


How to connect 2 vertices with edges? This sounds as a very basic question, I guess I just don't know proper terms to find the answer at once..

I'd like to create a complex polyhedron, so I'd like to create a tetrahedron first. Starting from a cube, I can get a figure like the one below (by deleting some faces and edges), but how do I connect those vertices with 3 missing edges?

Although the main question is the one in the title, other advices about creating a tetrahedron are welcome, too.

The answer is simple. Just press F between two vertices.

And your tetrahedron problem can be solved as follows:

Start with a Plane.
Delete one vertex and join all vertices with F to make a triangle.
Subdivide the triangle.
Go to the outer vertices and scale them on the xy axis to 0.
In the last step you only have to move the selected vertices on the Z axis by one.

That's it.

(Of course, don't forget to swap normals.)


Object doesn't appear in Final Render I just finished the Chair series by Blender Guru, but am obstructed with a problem.

In this picture you can clearly see the screws. This is Material Preview mode.
In the picture above is the viewport Cycles render. You can clearly see that there is nothing abnormal about the screws.

As soon as I press F12 to do a final render I get this problem. I don't understand why the screws are not appearing. I made sure that the screws are not turned off for render. I tried going to something called View Layer, and I checking Single Render Layer.
I am some what new to Blender, if someone could explain it properly for a beginner that would be appreciated.

Select your chair back and check the Subdivision Surface modifier, you have not given the same subdivision level in viewport and render, so it won't bend the same when rendered. You rarely need subdivision as high as 4, bring it back to 2, like you've done for render, and move the screws a bit so that you can see them correctly, then render.


Match shape key for mesh to size of text bounding box I'm trying to place text and then put text bubbles around them. To preserve the text bubble corner curves, I'm using shape keys. But sizing their width and height is a problem. I calculated width and height of the text bounding box and tried driving the shape keys, but that wasn't accurate for some reason.

Below is my second attempt. This time I'm calculating the width and height of both the text and bubble bounding box.

In the picture below;

I increase iterate a number of times to incrementally approach the correct size.
The result is used to increase the bubble size
The code seems to work but gets caught in a loop somehow. The bubble flickers through the sizes after hitting it's limit.

I'm missing something with the loop structure I'm sure. Any help would be appreciated.

If you know of a better, more elegant way to size the text bubbles around text, I'm open for that too.

Blend File

Animation Nodes have a node to compute the bounding box called Object Bounding Box Node. You can use it to get a rectangle (plane) that bounds each of the text objects, to get round edges, you can use the bevel modifier with the Vertex Only option, no need to use shape keys. To get the mesh of each bubble, get every 2nth vertex of the output bounding box vertices (Only every 2nth because the rest is the upper part of the box), then create a mesh out of it:

Which when joined, output and beveled will produces:

Which is exactly what you want, but you might want to scale the rectangles a bit to give the text some space inside, this is easily done by translating the upper-right, upper-left, lower-left and lower-right vertices a bit in the directions $(1, 1), (1, -1), (-1, -1), (-1, 1)$ respectively (They might not be in the same order as I mentioned, so check first !):

By changing the scale, we get different padding widths:

And by changing the bevel width, we can control the radius of the corners:


cant save as .blender I am A Sims4 user and I've been trying to create new hairstyle.
But I seem to be unable to save as .blender so i cant open it on blender

Do i have to download something else to be able to save as .blender?
I'm confused help please

The file type is .blend, but it is not a format you can just save to like an image file format. You will need to look for an exporter to go to maybe .obj file format or something like it that handles mesh and materials together.


working with 1m faces mesh. how to uv map/unwrap? im new to blender and dindt get into uv mapping jet. what im trying to do is uv map an landscape that has 1million faces. apart from uv mapping, just assigning my image wont work cause it is the wrong size (a bit too big). as far as i understand uv mapping helps me assign my image and cutting off what i dont need. so i want to ask: is it even possible to uv map/unwrap such a big mesh? and if so how to? or are there better ways to do that?

thanks for all answers.
-laurin

edit: i tried mesh>cleanup>limited dissolve in edit mode to reduce myface amount. i think my pc cant handle that. blender goes unresponsive (for 10 min now)

ok. after the comment of m.ardito i tried uv mapping with easier stuff. after i knew the basics i did my landscape again (using heightmap) with fewer faces. then i could unwrap it and assign my texture to it. after that i didsubdivide smooth a few times to get to an hihger detail grade.

no need to answer anymore.

sadly i cant accept my own answer right now. gotta wait 2 days.


How do I rotate the 3D cursor to match the rotation of a camera? I want to place a spot light right where my camera is and at the same orientation.
If I wanted to place, for example, a spotlight where a cube is and in the same orientation that I can easily do but I am stumped to how to do that with matching the angle of a camera.
So I place the 3D cursor at the active object, in this case the camera, but all the surface orientation or other option don't work. I tried every combination. I can't get the orientation to match the camera's angle.
How do I rotate the 3D cursor to match the rotation of a camera?

You can also do this without any addon :)

Select Camera
Object > Snap > Cursor to selected (Shift+S)
Look through your camera (View > Active Camera) (Numpad 0)
Add your spotlight and choose Align > View


Change the export stl file code from Exported from Blender-x.x.x to object name I want export model into stl format in ASCII, which Blender can do. However when I open the exported stl file by text, the first line is always like this:

solid Exported from Blender-2.91.2

And the last line is:

endsolid Exported from Blender-2.91.2

I want to change the string "Exported from Blender-2.91.2" to my stl file name, so I have to open my stl files again and again to change the name. This bothers me a lot and I don't know how to fixed it once and for all. I tried to open the addon folder io_mesh_stl(path:2.91\scripts\addons) and find in file stl_utils,line 75:

return "Exported from Blender-" + bpy.app.version_string

Is it because this line? How can I fix my problem? Thanks a lot if anyone can help!

Slippery Slope.
Would investigate doing this in a post pro way, Using something like sed   or python, to run thru stl files and automate the bothersome edit, rather than updating the addon code.
That said, a quick edit to change the header when writing to ASCII
stl_utils.py
def _ascii_write(filepath, faces):
    from mathutils.geometry import normal

    with open(filepath, 'w') as data:
        fw = data.write
        header = _header_version()
        fw('solid %s\n' % header)

        for face in faces:
            # calculate face normal
            fw('facet normal %f %f %f\nouter loop\n' % normal(*face)[:])
            for vert in face:
                fw('vertex %f %f %f\n' % vert[:])
            fw('endloop\nendfacet\n')

        fw('endsolid %s\n' % header)

change the code (circa line 205) from
header = _header_version()

to
header = filepath

or to hack it just to use the filepath stem "/path/foo/bar/stem.extension"
from pathlib import Path
header = Path(filepath).stem

or to hack it just to use the filname (with extension) "/path/foo/bar/filename"
from pathlib import Path
header = Path(filepath).name


Recursive Particle system I have a blue Suzanne. On that it should emit red balls. And on each red ball it should emit green box.

I have tried with Is it possible to recursively instance object particles?

But it does not really answer the question nor work and also does not work on animated objects. Or I am wrong in sequence.

No green boxes available in result:

Download current file: https://onedrive.live.com/redir?resid=AD9FE0A4134005AA!2480433&authkey=!ALz-h9Vlfrbekfs&ithint=file%2cblend

Answer is actually quite simple: this cannot work in current design - to simplify, objects as particles are not actual objects, but instances of objects, with quite limited sub-set of objects features. An instance cannot emit particles.


Enable experimental features Blender 2.72 I'm using Blender 2.72 and I want to enable the experimental feature set, which supports OpenCL for my AMD/ATI graphics card (I know what the risks are of doing this). Googling it, I found a Blender Wiki page of 2.6x which said I have to change the feature set to experimental, in the render menu, right under the display options (this is what I'm talking about). However, in my Blender 2.72 I don't have this option:

Could anyone help me to still get the experimental feature set to work?

The reason it's not appearing is because this option is only available in the Cycles render engine.

To switch to Cycles, go to the Info header (in the default layout, it's at the top) and change the engine to Cycles.


Undo and Redo on Macbook not functioning The CtrlZ and ShiftCtrl + Z combinations are essentially ignored on my Macbook. It's behaving like an unqualified Z key press.  How do I get that to work on Macbook or is there another means of performing undo/redo?

On Mac OS X the keyboard shortcuts for undo and redo are CmdZ and ShiftCmdZ, consistent with other applications on this operating system.


How can I morph an object into a liquid and back to a different object? I suppose I found nothing about because I don't know the proper technique name/terminology.

I'm working in my first videogame, an adventure-suspense walking simulator. I need to know techniques/tools/modifiers/plugins names about the next example.

I have a genetically modified character who can transform into a liquid, and reverse, the sequence it's he has one single hair of himself, drop it in a table, then the hair transforms into a grey liquid drop, and the drop transforms progressively into a flower.

I need that technique in reverse as well, to transform some liquids coming from different places progressively into the characters body.

Can someone give me an approximation about what I need to know? Thanks in advance.

I think the terminology you want is "Fluid Control".  If you google "Blender Fluid Control", you will find some tutorials on YouTube that will make fluid crawl up onto a shape (Suzanne for instance).  Then I think the compositor is your friend.


Identifying faces from the UV map A 3D model I work on seems to create some artifacts from the unwrap function:

These faces in a straight line don't seem to correlate with any faces I have actually wanted to have in the model, but I can't select vertices on the UV map and then see them marked on the main edit window - which makes hunting down these artifacts for removal seemingly impossible. So far I have tried to merge by distance for no result, they seem to be distributed all over the item.

Assuming you have got the Sync Selection button checked:

(The double arrow on the left)
Then, deselect all in the UV window, except the vertex of interest, mouse over the 3D View, and hit Shift H to hide all but your selection. Still no sight? Hit Numpad  .  (period) to center the view on the selection.


Segmentation Fault when calling bpy.ops.render.render (script using Blender as a Python Module on Mac) I am using Blender as Python Module on Mac and now attempting to create a scene programmatically and take a screenshot of what the camera sees but I am getting a "Segmentation Fault: 11" when running the following script (on calling bpy.ops.render.render).

import bpy
import mathutils
import bmesh

scene = bpy.context.scene

# Create the cube
mesh = bpy.data.meshes.new('cube')
ob = bpy.data.objects.new('cube', mesh)
scene.collection.objects.link(ob)
bm = bmesh.new()
bmesh.ops.create_cube(bm, size=1.0)
bm.to_mesh(mesh)
bm.free()

# Create a light
light_data = bpy.data.lights.new('light', type='POINT')
light = bpy.data.objects.new('light', light_data)
scene.collection.objects.link(light)
light.location = mathutils.Vector((3, -4.2, 5))

# Create the camera
cam_data = bpy.data.cameras.new('camera')
cam = bpy.data.objects.new('camera', cam_data)
scene.collection.objects.link(cam)
scene.camera = cam

cam.location = mathutils.Vector((6, -3, 5))
cam.rotation_euler = mathutils.Euler((0.9, 0.0, 1.1))

# Render settings
scene.render.image_settings.file_format = 'PNG'

filepath = "/tmp/image_blender.png"

# Segmentation fault caused by this line
bpy.ops.render.render(write_still = 1)

img = bpy.data.images['Render Result']
img.save_render(filepath, scene=scene)

I'd love to get some help and understand if there's an issue with the script or with the way I installed/configured Blender as a python module. Thanks in advance!

P.S.: Copy/Paste of Problem Detail and System Configuration

I experienced this same error with the bpy module on MacOS 10.15, python 3.7.7 and blender 2.83/2.82

I was able to fix it by changing to a different renderer.

you can add this line: bpy.context.scene.render.engine = 'CYCLES'

before: bpy.ops.render.render(write_still = 1)

And it will no longer seg fault


Problem painting through model in overlapping uv area I'm trying to texture paint this model but there is a problem at the hand guard area at the front of the gun. I want to paint through the model to get both sides while in right view. I turned off occlude in the options to do this but then I get the problem. There are overlapping uv's in this area from the barrel inside the hand guard. I hid the inside barrel's uv's/mesh in edit mode to paint but when I go into texture paint they are visible again.

Blend file

Moving the uv's to an unused space will work.

From the blender manual for v2.79 overlapping uv's are not supported:

"Known Limitations

UV Overlap

In general overlapping UVs are not supported (as with texture baking).

However, this is only a problem when a single brush stroke paints onto multiple faces that share a texture."

So the only solution really is to delete the part or move the problem uv's to an area that is not used. The original uv's are set by someone else but since the part is not seen it doesn't matter.


How to unparent a deleted armature? I deleted a armature without unparenting it, and now it is affecting my particle system for some reason. The hair particles do not look like they do in particle edit mode, they go in all kinds of directions. Before I parented the armature, they did not do that. What should I do?

there are 3 things you can do manually, both in properties panel :

Remove the armature modifier (click the 'X')

remove the parent manually in object properties (click the 'X')

remove the armature related vertex group in object data tab (select a group and click the '-' button)


X AND Y Directions in this Script I got this script, which adds a slider in a tab for rotating Z axis.

i also want to rotate X and Y, so the user can adjust all of them.

how i can add these two axis to this code:

Thank you very much for you help :)

import bpy
from bpy.props import FloatProperty
from mathutils import Vector, Matrix, Quaternion, Euler
from math import degrees, radians

class HelloWorldPanel(bpy.types.Panel):
    """Creates a Panel in the Object properties window"""
    bl_label = "Hello World Panel"
    bl_idname = "OBJECT_PT_hello"
    bl_space_type = 'PROPERTIES'
    bl_region_type = 'WINDOW'
    bl_context = "object"

    def draw(self, context):
        layout = self.layout

        obj = context.object

        row = layout.row()
        row.label(text="Active object is: " + obj.name)
        row = layout.row()
        row.prop(obj, "name")

        row = layout.row()
        row.prop(obj, "rotate")

def get_rotation(self):
    return self.rotation_euler.to_matrix().to_euler('ZYX').z

def set_rotation(self, value):
    rot = self.rotation_euler.to_matrix().to_euler('ZYX')
    rot.z = value
    self.rotation_euler = rot.to_matrix().to_euler(self.rotation_mode)

def register():
    bpy.types.Object.rotate = FloatProperty(name="Rotation",
            description="Rotate object.",
            get=get_rotation,
            set=set_rotation,
            unit='ROTATION')

    bpy.utils.register_class(HelloWorldPanel)

def unregister():
    del bpy.types.Object.rotate
    bpy.utils.unregister_class(HelloWorldPanel)

if __name__ == "__main__":
    register()

Here is a proposal for the first question, without using the matrix conversion (not sure why it's necessary there?). Does it work for you?

import bpy
from bpy.props import FloatProperty
from mathutils import Vector, Matrix, Quaternion, Euler
from math import degrees, radians

class HelloWorldPanel(bpy.types.Panel):
    """Creates a Panel in the Object properties window"""
    bl_label = "Hello World Panel"
    bl_idname = "OBJECT_PT_hello"
    bl_space_type = 'PROPERTIES'
    bl_region_type = 'WINDOW'
    bl_context = "object"

    def draw(self, context):
        layout = self.layout

        obj = context.object

        row = layout.row()
        row.label(text="Active object is: " + obj.name)
        row = layout.row()
        row.prop(obj, "name")

        row = layout.row()
        row.prop(obj, "rotate_x")
        row.prop(obj, "rotate_y")
        row.prop(obj, "rotate_z")

def get_rotation_z(self):
    return self.rotation_euler[2]

def get_rotation_x(self):
    return self.rotation_euler[0]

def get_rotation_y(self):
    return self.rotation_euler[1]

def set_rotation_z(self, value):
    self.rotation_euler[2] = value

def set_rotation_y(self, value):
    self.rotation_euler[1] = value

def set_rotation_x(self, value):
    self.rotation_euler[0] = value

def register():
    bpy.types.Object.rotate_x = FloatProperty(name="Rotation X",
            description="Rotate object.",
            get=get_rotation_x,
            set=set_rotation_x,
            unit='ROTATION')
    bpy.types.Object.rotate_y = FloatProperty(name="Rotation Y",
            description="Rotate object.",
            get=get_rotation_y,
            set=set_rotation_y,
            unit='ROTATION')

    bpy.types.Object.rotate_z = FloatProperty(name="Rotation Z",
            description="Rotate object.",
            get=get_rotation_z,
            set=set_rotation_z,
            unit='ROTATION')

    bpy.utils.register_class(HelloWorldPanel)

def unregister():
    del bpy.types.Object.rotate
    bpy.utils.unregister_class(HelloWorldPanel)

if __name__ == "__main__":
    register()


NDOF Invert Blender 2.8 Is it possible to invert the NDOF pan and orbit and zoom directions in 2.8?

2.7 had an option to customise this. I use the default 3Dconexion settings but blender automatically flips them.

Blender now responds to changes made in the 3DConnexion properties application (this wasn't previously the case in 2.79).
If you reverse all the navigation properties in the 3DConnexion advanced settings, the space mouse will respond as if it was set up with default settings in Blender. In every other CAD program I have used the opposite is true.

I can't seem to find any documentation of these changes or why it is mapped wrong by default.


Matt Cap Shading texture Is there a way which a matt cap can be rendered? I really like this shinny white texture. I tried to simulate it with the basic nodes, but doesn't quite match. Also when I try to render it's loosing it's glossiness which is more visible in the view port shader.

Thank you

Go to Render Settings and switch the render engine to Workbench. This is the render engine the viewport uses and is responsible for matcap lighting.

Then select the Matcap you want to use just like you would do from the viewport by using the Lighting dropdown below the Sampling menu. Once you press render, each frame will be created using the lighting type that you have specified. It also renders lighting fast because Workbench is designed to provide instantaneous shading for the viewport.

No fancy node editor work required, just switch the render engine, choose a matcap, and that's about it.


Displace Mesh along Curve on single axis I am modeling bridges and want to use a curve to shape them. However I only want the vertices to move along a single axis (like Z).

With the Curve Modifier, the panels don't hang straight downwards.

Create a constant-offset array of a single mesh edge, crossways to the bridge-curve..
Set the arrayed edge's duplication to Dupliverts
Parent the vertical elements to the array of edges?

This might not suit .. there are other options, particles on placeholder planes, parenting with constraints..


Multiple KeyErrors leading to segfaults with custom properties I know that Segmentation Fault is some sort of memory error having to do with C and C++ - beyond that I don't really know how to handle it. I read up on this error through this post on stackoverflow, and this post on multi-file registering/unregistering but still don't have much of a clue.
I am experimenting with custom properties, sliders and operators. Everything as far as I can tell is accessing what it is supposed to (as in, I adjust the slider and the appropriate object's value is updated) but I am getting a bajillion KeyError's and then Blender crashes with a segfault.
Code
# Functions/Callbacks

    def get_rotate_cam(self):
        return self["Rotate Camera"]

    def set_rotate_cam(self, value):
        self["Rotate Camera"] = value

    def update_rotate_cam(self, context):
        for obj in bpy.context.selected_objects:
            bpy.ops.opject.select_pattern(pattern="Camera")
            obj.rotation_euler[0] = get_rotate_cam_x(self)

#Property Group

    class SliderProperties(bpy.types.PropertyGroup):
        bpy.types.Scene.rotCam = FloatProperty(
            name="Rotate Camera",
            description="Rotate the camera with the slider"
            default=0,
            min=0,
            max=360,
            update=update_rotate_cam,
            get=get_rotate_cam,
            set=set_rotate_cam
        )

#Panel

    class EditStuff(bpy.types.Panel):
        bl_label = "Edit"
        bl_space_type = "VIEW_3D"
        bl_region_type = "TOOLS"
        bl_context = "objectmode"

        def draw(self, context):
            layout = self.layout
            layout.prop(bpy.context.scene, "rotCam")

# Registration

    def register():
        bpy.utils.register_module(__name__)
    def unregister():
        bpy.utils.unregister_module(__name__)

    if __name__ == "__main__":
        register()

So I am clearly doing something super inefficient here, I'm just not sure what it is. What is also throwing me off is when I use the custom slider once, clear the terminal, I don't get the KeyError any more. That has me thinking that it is some sort of initialization or context shenanegains going on. Hanging pointer maybe? Just not sure.
I also have a similar set up with compositor nodes to adjust things like shadows. Everything works correctly, I can adjust the shadows, but the KeyError makes Blender crash.
Thanks for the help!

I might be mis-interpretting your question but, this works:

import bpy
import math

def update_rotate_cam(self, context):
    v = bpy.context.scene.rotCam
    bpy.data.objects['Camera'].rotation_euler.x = math.radians(v)

class SliderProperties(bpy.types.PropertyGroup):
    bpy.types.Scene.rotCam = bpy.props.FloatProperty(
        name="Rotate Camera",
        description="Rotate the camera with the slider",
        default=0,
        min=0,
        max=360,
        update=update_rotate_cam,
    )

class EditStuff(bpy.types.Panel):
    bl_label = "Edit"
    bl_space_type = "VIEW_3D"
    bl_region_type = "TOOLS"
    bl_context = "objectmode"

    def draw(self, context):
        layout = self.layout
        layout.prop(bpy.context.scene, "rotCam")

def register():
    bpy.utils.register_module(__name__)

def unregister():
    bpy.utils.unregister_module(__name__)

if __name__ == "__main__":
    register()

In python a safe way to access items using a key is often done this way:

# returns None if key isn't found
v = some_collection.get(key_name)

# or provide the fallback value if not found
v = some_collection.get(key_name, fallback)


How can I build a versatile camera rig which can both orbit around its focus and pan? This is a little hard to put into words, so please bear with me.

I'm building a camera rig. I need the camera to be able to orbit around an object, as if it were on a circular track, then move away from that object and then pan. Here is an example of the kind of motion I'm after:

The problem with the motion in the example is that the camera is initially rotating around an empty to which it is parented (the black circle) but then when it rotates around its own axis, it leaves the empty behind, and so will never be able to orbit again.
Essentially I want to be able to choose whether the camera rotates around the empty or the empty rotates around the camera at any given time and then animate back and forth between these two possibilities.

The final rig will be using bones and constraints to allow for crane shots and the like, so a solution doesn't need to just rely on the relationship between camera and empty.

You need to be able to orbit at different distances and that means you need dynamic parenting. The way to achieve this is through Child Of Constraints. To animate this, you need to do the following in this specific order:

animate the camera into the start position of orbiting, till now the camera has no parent, it is free
place Child Of Constraint onto the camera, target is the orbit control empty, press Set Inverse button - now the camera is parented to empty
animate the orbiting motion by rotating the empty and any local motion of the camera (panning while orbiting etc..)
on the last keyframe of orbiting, insert a keyframe for the camera (LocRot) and a keyframe for the influence of the Child Of Constraint (100%).
move 1 frame forward
select camera and choose Object > Apply > Visual Transform, do not move the timeline
keyframe the Child Of Constraint to 0%
keyframe the camera (LocRot)
you can move the timeline now
the camera is now free again, without any parent
repeat and profit, camera will have as many parent constraints as there are orbiting motions

This is a bit tedious, if you are up for the rigging job you can put this into a script that can be run with a custom button in UI to dynamically parent and un-parent.

There is this addon which for simple use cases will work fine, but it is limited. This is very tricky to setup inside the hierarchy of an armature (for example dynamically parenting hand to thigh) when all is also parented to the Root (the trick is to avoid double transforms with some clever drivers).

And if you are trying to do this on a linked armature, it is yet again even bigger challenge, because after file reload all drivers on constraints that are not present in the original rig, but are present in the animation where the rig is linked are discarded.

For completeness and best result I am also plugging this in:

How to smooth camera animation to have fluid feel?


How to motion track green screen footage and paint out the tracking markers I've been trying my hands at VFX within Blender for the past couple of days. I've got a few clips that have been shot against a green screen with tracking markers. I looked at a couple of tutorials and learned how to key the green screen and motion track. However, I couldn't get rid of the tracking markers - I tried masking them out but to no avail. I thought it would be pretty straight forward but I guess I was wrong. One of the reasons could be that I'm not used to the node based compositing inside Blender.
How would you go about doing what I'm struggling with. This is the sequence of how I am trying to achieve this.

Import the green screen footage inside the video editor and export a png sequence.
Start a new project. Reimport the png sequence inside Blender and track the markers within the footage.
Key the green screen out.

What do I do next ? I tried creating a couple of masks that covered a number of static tracking markers but I can't seem to get rid of them. I also tried opening the same image sequence inside the Editing tab after having done all this and connected the mask to an adjustment layer - I can see that the markers have disappeared in the Video Editing workspace but it doesn't show up in the compositing window. This makes me really confused - Why do I have to reimport the video in the Editing tab when it's already open in the Motion tracking tab ?
Again, let's say that I successfully key the green screen and remove the tracking markers. I suppose I should stay within this project file if I want to add 3D models around the footage. Am I right ?
I am a complete noob so I would really appreciate if someone could help me out. Thanks in advance :)

Okay. I found a solution to my problem by creating masks and combining them with a Mix node. Plugging the mix node into the garbage matte of the Keying node gets rid of the markers on the green screen. The difficult part is to keyframe the masks one by one but it's alright since I know it will get the job done.
However I am wondering if there's a smarter way to get this done.


Most efficient way to round edges In this simple model I first rounded the corner edges of the shape using bevel, with 16 segments (1st pic). Then I selected everything and applied a second very small bevel of 1 segment, to give the hard edges a softer look (2nd pic).

I am happy with how it looks, but is there a better way to do it? By better I mean more efficient, and looks as good or better.

I know I could use the subsurface modifier for rounded edges as well, but read that bevel is more efficient and gives more control. I guess the efficiency will be lost if I use too many segments. But I don't know at which point this becomes true; is it something I need to worry about, or is bevelling so much more efficient that it is not realistic that it ever becomes more costly than sub-surfacing?

Is there an even better way to handle the two types of rounding in this model?

There is no most efficient way to effectively round edges, this is highly dependent on what type of object you are modeling, how much detail you want, how close you plan to render, the environment your model will be in etc.

There are several ways to go about this, all highly effective depending on the situation they are use in. I would recommend to continue beveling your edges.

Why? Beveling is much more efficient and cheaper than subsurf, you also have better control of your geometry and topology. What you are doing above is using it inefficiently, that shape could be just as rounded with fewer segments, You don't need more than a few or so segments on any edge at a time. It is also worth noting that since it is a modifier, any mistakes you make can be easily undone.

Here are is an object duplicated twice and bevelled with different amount of segments, one has 12 segments and the other has 6, can you immediately tell which one is rounder?

Here are the wires..

As you can see it is highly efficient, it's all in how you use it. As you have it above is overkill for such a simple object, you don't need more than a few segments to round out your edges depending on the complexity of your mesh.

Note: Also using Shade Smooth on your hard surface models can help to make them appear more smooth/round and less faceted as I have done on the objects in the images above. You can also just smooth certain parts of your mesh by selecting the vertices/faces and using the same method.

Also, feel free to use a mixture of modifiers to achieve your final shape or effect, for some objects it is better to use subsurf with edgeloops and for others, subsurf with creases etc. There is no one good or most efficient way to go about it, It all depends on what you need, the model being used and how well you as the artist can determine what the best way to go about it is.

Additionally, you can get more tips here:

How can I make sharp geometric 3d models look more realistic?
How to smooth shade an object while retaining hard edges?


game engine hides cursor (windows 8.1/parallels) Also a OS X 10.12.5 issue. Just installed blender 2.78 on windows 8.1 under parallels. When I start the game engine, the cursor disappears when it enters the blender window. Crtl-alt to release the cursor doesn't help. changing the settings to optimize or not for games doesn't help.

Different problem on blender install directly on the mac (10.12.5). Here, when I start the game engine the blender window just flickers rapidly and becomes entirely unusable.

In both cases everything is fine until the game engine starts.

Any guesses?

To see the mouse cursor when bge is running active Mouse cursor checkbox in render tab of property panel.

Or use a script to show the mouse cursor.

You can use logic or render to show the mouse cursor while BGE is running.

Using bge.logic.mouse

 from bge import logic
 logic.mouse.visible = True # 1 or True are acepted, to disable 0 or Flase

Using bge.render.showMouse()

from bge import render
render.showMouse(1) # 1 or True are acepted, to disable 0 or False

NOTE: When BGE is running you are unable to make change to configurations, property, objects, scripts, etc.


How do I add the ability to import Collada files to Blender 2.76? As you can see from this screenshot, there's no option to import Collada files. There IS such an option in this question here. Was this removed at some point? Is it not available on the Linux version?

My deleted earlier answer failed to take into account the fact that you are working from a Linux (apparently Debian) distribution. My frame of reference is on Windows, where the ability to import and export Collada files has been part of the default distribution since at least version 2.63, but I don't know that this is true with the versions for distributed by, or for, Debian.

I note in your comment to your question an error message "This PPA does not support xenial"; a quick search of the web shows that the name "xenial" is associated with an Ubuntu Linux distribution, though I'm not sure how this affects your situation.

If I were in your positon, I would first check with the appropriate individuals to see if the capability is been disabled in the Debian distro; if it is, then I would try uninstalling, and reinstalling Blender. If the capability is not part of the Debian version, there is an addon for Blender to import and export Collada files on Sourceforge, but I have no information as to how well it works, especially under Linux. Otherwise, if you have the skillset, you might try downloading the tarball for Blender directly from the Blender.org site and try to install Blender from there, though if you do that much work, you might as well upgrade to 2.77a.


How to map keys in Blender 2.80? I'm using Blender 2.80 and I need to map the "view selected" / "frame selected" for a different key because I'm using a notebook that doesn't have the numpad. How should I proceed?

You can change shortcuts in the Keymap section of the Blender Preferences. Just open up the preferences and search for either the name of the function you want to remap, which in this case is 'view selected' and all the bindings for it will appear. You then simply click on the current shortcut and Blender will ask you to press the key you want to change it to.

Note that in Blender 2.80 you can also bind keys by right-clicking on buttons or options in menus and selecting 'Assign Shortcut'. Since the frame selected function doesn't appear on any menus, it must be assigned in the preferences.


Blender 2.8 Copy 50% bone rotation between different local axis I am trying to make the Bone 1 copy 50% rotation of Bone 2, as below. Mixed axis of the bones make it difficult. Please, what should I do? I spent hours trying, I will do everything you say.

I created a fresh armature in simplest way, and found that Local Y axis in bone 1 is Local axis Z in bone 2. Why does this happen? I would expect the bones to have the same local axis alignment?

Is there a way to make Local Y rotation of Bone 1 copy the Local Z rotation of Bone 2 with 50% influence?

If the orientation of a bone is not correct you can change it in Edit mode with ctrlR (manual), or ShiftN (automatic). To display the axis go in the Properties panel > Object Data > Viewport Display > Axes.

Now if you want a bone to influence the rotation of another bone, in Pose mode, you can give the second bone a Copy Rotation constraint (in my case Space: Local Space - Local Space) and reduce the influence value to 50% if it needs to.

If you want the second bone to copy the rotation of the first one, but on a different axis, use a Copy Transformation constraint. For example here I want bone2's Y axis rotation to copy bone1's X axis rotation. I need to set all the values properly.


Bone heat weighting: failed to find solution for one or more bones error hair I've got huge problem.I am trying to connect hair to rig, but all the time this error appear. I tried removing doubles, applying mods and other smart tricks i found on this forum, but still fails. If anyone have any idea how to fix it I would be thankful.

I drop my blend file:

Automatic weights is an useful shortcut to speed up the weighting process, but every complex character will need some handmade fine tuning: you can rely to automatic weights only if the character is a single-piece mesh, manifold, no doubles, no crossings, ecc .... In your case there are lots of different spare parts. The hair, in particular, has inverted normals; after you recalculate normals you can select all hair mesh, then shift select the armature, go to pose mode, unselect all, select the head bone and Ctrl+P, "bone" option: in this way, hair will be strictly parented to the head bone, without any weight issue. Then you will have to fix all the dress problems ... Good luck, and start using manual weighting (my favourite way is "with empty groups": this option creates empty vertex groups that can be manually weighted in edit mode).


What are the most efficient workflows to create all quad junctions? In a video tutorial on All Quad Junctions some different  types of junctions are explained. When trying to create them I struggle with extra edges and merging points, ripping points. That takes too much time

Is there a efficient reproduceable way to create these types of junctions?

The easiest way that comes to mind currently is to remove  the critical faces, add some loop cuts, then create faces.

So for the second one, you would remove the critical face,
make a double loop cut with Ctrl R
then 2 then extrude the small edge in the middle,
and finally select the edge pairs to Fill them with F.

The same applies to the third and fourth with some changes. For
the first one: Remove the upper two critical faces, add the loop
cuts, fill the proper edge pairs, move the center vertex down.


What happens with the quality of sound if I render it twice as MP3? I'm working with many stripes of  uncompressed WAV sounds. Now I want to make them be just one MP3 stripe.

My problem is: There is other files to render in the same situation. So in the end,  there will be files rendered as MP3 in need to be rendered again as MP3 to obtain the final cut.

I would like to know what Blender does in this situation: Does the quality goes down even more?

It boils down to if you are increasing the compression or not, and has nothing to do with Blender.

The reason for this is that any given level of compression will "shape" the encoded values into the compressed shape required. Subsequent compression at the same degree using the same compression technique seeks the exact same shape. Given that the algorithm is seeking the shape the data is already in, very little further degradation will occur typically.

You can test this by trying to encode a JPEG image twice at the same compression level. What you should observe is very little encoded data value shift, and even possibly a growth in file size.

As a general rule, this is a poor option for a pipeline, and it would be much more prudent to keep your interchange data in a lossless and uncompressed format, and encode once and only once. Even expanding an MP3 to a WAV can help you here in theory.


How do I export this mesh to a obj? I'd want to export this mesh to an OBJ and open it in Spark Ar but in Spark it only opens the faceMesh layer

I'm not familiar with Spark Ar, but maybe this can help you out: https://www.reddit.com/r/blender/comments/3nfr7c/export_only_vertices/


Material disappears after using quick explode? When I place an image texture on an object it works fine, the material shows up and looks good. I then go and place a quick explode effect on the same object and my material goes away. Can someone help we with this?

Before

--

After

I've found there's a difference between Quick Explode and the Explode Modifier.  Quick Explode seems to remove materials, perhaps a bug (I'm on Blender 2.76).  Instead of using Quick Explode, just apply the Explode Modifier to your object instead.  You should find that your materials remain.


How would I make a good plastic reflection How would I make a good plastic reflection for this object?

the black is pretty ok but the colored tiles need a better reflection

The reflection will look better if the surrounding light is set as a complex scene (HDR 360 image).

These cube use the same material but the left one is using simple lighting and the right one use a HDR environment.

The reflection draw details on your cube face and for simple light it just look plain.

BTW, you should make those face bump out a little bit to make the edge catch reflection.


Smooth Shading option not working https://drive.google.com/file/d/1q3kcN4hKMkdARc4XzEbYOsSwoWuhSzKA/view?usp=sharing

Here's my Blender File

I can make the object active.

But when I click the smooth option, nothing happens.

It looks like most of the faces in the model are disconnected. When you activate smooth shading on disconnected faces, Blender treats each one individually and it looks like flat shading because each face's boundary is handled independently from its neighboring faces.

It's best to model (or import) objects with connected faces if you want to use smooth shading, but here is a quick and dirty way to join most of the faces in your model:

Select the object.
[TAB] into Edit Mode.
[A] to select all vertices.
Mesh > Vertices > Remove Doubles

This will join most of the faces and you will get smooth shading for the most part. You will probably need to manually repair some faces to get it working across the entire object.


Possible to add a plane using vertices via Python? I've successfully created a plane mesh in Blender by first specifying the coordinates of the four vertices in a .obj file and then importing this file into Blender.

Is directly adding a plane using vertex coordinates via Python possible?

Python function bpy.ops.mesh.primitive_plane_add allows users to add a plane, but it takes in radius, location, rotation, etc. instead. I don't see a quick and easy way of converting four vertex coordinates into these parameters.

With this code you can set the vertex location  manually:
import bpy

def create_custom_mesh(objname, px, py, pz):

    # Define arrays for holding data
    myvertex = []
    myfaces = []

    # Create all Vertices

    # vertex 0
    mypoint = [(-1.0, -1.0, 0.0)]
    myvertex.extend(mypoint)

    # vertex 1
    mypoint = [(1.0, -1.0, 0.0)]
    myvertex.extend(mypoint)

    # vertex 2
    mypoint = [(-1.0, 1.0, 0.0)]
    myvertex.extend(mypoint)

    # vertex 3
    mypoint = [(1.0, 1.0, 0.0)]
    myvertex.extend(mypoint)

    # -------------------------------------
    # Create all Faces
    # -------------------------------------
    myface = [(0, 1, 3, 2)]
    myfaces.extend(myface)

    mymesh = bpy.data.meshes.new(objname)

    myobject = bpy.data.objects.new(objname, mymesh)

    bpy.context.scene.collection.objects.link(myobject)

    # Generate mesh data
    mymesh.from_pydata(myvertex, [], myfaces)
    # Calculate the edges
    mymesh.update(calc_edges=True)

    # Set Location
    myobject.location.x = px
    myobject.location.y = py
    myobject.location.z = pz

    return myobject

curloc = bpy.context.scene.cursor.location

create_custom_mesh("Awesome_object", curloc[0], curloc[1], 0)

I hope this helps!


Mesh is Grey after adding an Image/Texture to a material I need some help making a mesh colorful. The image I add to a material does not show up on my mesh. A snippet of the code is below

# Create new mesh
mesh = bpy.data.meshes.new("Landscape_Data")

# Make a mesh from a list of verts/edges/faces.
mesh.from_pydata(verts, edges, faces)

# Update mesh geometry after adding stuff.
mesh.update(calc_edges=True)

obj = bpy.data.objects.new("Landscape", mesh)
obj.data = mesh

# Link mesh to scene
scene = bpy.context.scene
scene.objects.link(obj)
obj.select = True

def material_for_texture(fname):
    img = bpy.data.images.load(fname)

    tex = bpy.data.textures.new(fname, 'IMAGE')
    tex.image = img

    mat = bpy.data.materials.new(fname)
    mat.texture_slots.add()
    ts = mat.texture_slots[0]
    ts.texture = tex
    ts.texture_coords = 'UV'
    return mat

obj = bpy.data.objects['Landscape']
mat = material_for_texture("C:\\Users\\Kyle\\Documents\\DTEEC_019358_2225_018857_2225_U01.ca.jpg")

if len(obj.data.materials)<1:
    obj.data.materials.append(mat)
else:
    obj.data.materials[0] = mat

Example: https://i.stack.imgur.com/jbNjK.png

The material looks like it loads the image but does not put it on the mesh

I can see you're using Blender Internal. Use Viewport shading  and select Material to see your image or texture in the viewport. And to achieve what you want, create new image in the UV editor, open the texture in it and unwrap the mesh. Scale down the UVs if necessary to have them inside the image area.


How make UV Textured mesh with material instead of specific colour? Just trying to replicate table with epoxy. But can't figure out how to create a complex material.
I have a textured table top but can't replace black strip with a material.

Eventually, I wanna get something like this:

But when I am using mix shader it turns blue:

I understand there should be some mask but can't figure out how to do that.

Just figure it out. Need to add RGB BW and do some math rules, but would be glad if someone will present more correct or convenient way of doing that


Mapping an algorithm to an animation I have written an algorithm that can compute fingering of piano scores.

Now I would like to have a 3D animation of a pair of hands playing this score. Each finger is already assigned to a key.

How could I use blender api for this. If it is possible at all?

Here is a very basic example of what you're trying to achieve:

A control file holds some data in the format
Frame-no obj_name,value of 'Key 1'
I have only created 2 shape keys (basic and 'Key 1') to test the script.

1 Finger1,1
1 Finger2,1
1 Finger3,1
1 Finger4,1
10 Finger1,.5
20 Finger2,.5
30 Finger3,.5
40 Finger4,.5
50 Finger1,1

The python script reads the control file and adds keyframes for each line

import bpy

filename='C:\\dev\\finger_shape.txt'

for line in open(filename):
    line=line.rstrip("\n")
    # Only append lines that have space in them.
    if line.find(" ") != -1 and line.find("#") == -1:
        # Split non comment lines of the format: Frame-no obj_name:value of 'Key 1'
        frame,obj_key= line.split(" ")
        obj,value=obj_key.split(",")
        bpy.context.scene.frame_set( int( frame ))
        bpy.context.scene.objects.active = bpy.data.objects[ obj ]
        bpy.context.object.data.shape_keys.key_blocks['Key 1'].value = float(value)
        bpy.context.object.data.shape_keys.key_blocks['Key 1'].keyframe_insert('value')

Result:

Regarding you comments on automatise the rendering you might find these posts interesting:

Is there a way to batch render multiple scenes?
Blender rendering automation (build script)

Parsing XML is not blender related but you should find examaples on SO:

https://stackoverflow.com/questions/1912434/how-do-i-parse-xml-in-python


Importing SVG files without losing transparency data I've been using Blender to make things like these: stylized vector illustrations made with Inkscape or Illustrator, imported as layered transparent pngs into Blender. The effect is easier to understand if you watch the youtube video.
https://www.youtube.com/watch?v=7_wQ-odwxQg

I'm using transparent PNGs because SVGs shapes imported into Blender loose their transparency data.
Imported SVGs come with color information all right, but it would be great if one could import SVGs into Blender without losing the transparency data of the individual shapes. I imagine for each individual shape an emission shader with the color information plugged into a mix shader node along with a transparent shader, with the transparency data used as fac.
My question: is that import procedure feasible with a script or a plugin?

The SVG importer is very basic, it will not deal with any effects used on vector drawing programs, you can only import the path and color, no alpha.
But even if you manage to import the alpha channel, the different paths would end up overlapping on the same plane, creating Z-fighting problems.
An alternative solution would be to rasterize the paths as different images.
Then use the import images as planes and select all of the images at the same time to import.
On the top right of the import window, click on the gear icon to reveal the options for the importer.
There is an option to offset the imported images on a particular axis and determine the offset distance:

If you use the $Z$ axis you should get a lineup like this:

For cycles you might need to increase the number of Transparency bounces in the light path section of the render properties.
You might need to adjust the clip distance for camera and viewport, so that you don't run into Z-fighting issues.


Move a set to another scene even though it’s done I have finished my video, but I put everything in one scene. There are a total of four sets. Is it possible to move a set to another scene  and render that other scene by itself or is it to late?

Just create a new scene.

(source: blender.org)

You can then choose to link or copy your assets

(For 2.8)

(blatant quote from the blender manual)

  New

  Creates an empty scene with default values.

  Copy Settings

  Creates an empty scene, but also copies the settings from the active scene into the new one.

  Link Objects

  This option creates a new scene with the same settings and contents as the active scene. However, instead of copying the objects, the new scene contains links to the objects in the old scene. Therefore, changes to objects in the new scene will result in the same changes to the original scene, because the objects used are literally the same. The reverse is also true.

  Link Object Data

  Creates new, duplicate copies of all of the objects in the currently selected scene, but each one of those duplicate objects will have links to the object-data (meshes, materials and so on) of the corresponding objects in the original scene.

  This means that you can change the position, orientation and size of the objects in the new scene without affecting other scenes, but any modifications to the object-data (meshes, materials, etc.) will also affect other scenes. This is because a single instance of the “object-data” is now being shared by all of the objects in all of the scenes, that link to it. This has the effect of making a new independent copy of the object-data.

  Full Copy

  Using this option, nothing is shared. This option creates a fully independent scene with copies of the active scene’s contents. Every object in the original scene is duplicated, and a duplicate, private copy of its object-data is made as well.


Remove Object and part of object its overlapping How would I remove the selected object and the part of the other object taken up by it?

There are a few ways to do this.

Using Boolean operations:

In Edit mode

Both pieces have to be part of the same object.

On the selected piece use Mesh>Faces>Intersect(Boolean)

In Object Mode

Both pieces have to be different objects.

Select the one that is to be cut. And add a boolean modifier and use the other object to intersect.

This method has the advantage of being non destructive and interactive. If you need to reposition or alter the cutting object you can do it and the affected object will be recalculated.

At this point you can choose to hide other object or Apply the Modifier to make the change permanent and delete the cutting object.


I pressed c in editing mode and can't get back can somebody help me? I'm on my Mac Book Pro (without Numpad - I KNOW) and I need a shortcut or something to untag the object. I can't press any other button and I don't know when I saved it the last time. Please help meeee.

the Esc key should get you out if it. You can also use your non-dominant click(left or right).


Color Mixing with textures and different objects? I was wondering if there is a way to make mesh appear a different color when you put another mesh over it.

Kinda like the picture shown above on how the circles are mixing to create a new color or even make a glowing object appear dark when another object is hovering over. Thank you.

Well, since Cycles is a physically-based engine... you can use a physically-based solution :).


How to add an action to a material? I'm trying to create a traffic light in blender, I assigned all the needed materials(3 colors), I created animation for each color, but in the Dope Sheet Window, when I choose Action Editor there is no any actions.  And when I exported the object as fbx and imported to Unity the animated colors doesn't work.

Any solutions? Thank you very much

I am not sure about material action support in unity, however I am pretty sure you can use a UV animation,

Just move the lights face to a copy of the face lit up?

http://answers.unity3d.com/questions/19848/making-textures-scroll-animate-textures.html

This way you just need the 'lit up' texture face in the uv sheet for each color.


Have a doubt on Recalculate option in Shading Option? I can't understand why and when should I use Recalculate operator in Shading Options?

Recalculate Normals function is used when you're modelling and some inappropriate dark areas appear. Recalculating the normals is used to fix this problem.


My global axes got rotated My global axes are not not level anymore. How can I reset?

So I don't mean an object, but the actual coordinate system.

As Mr Zak and Brenticus pointed out in the comments:

Those arrows are always aligned to the global coordinate system and are rendered from the point of view of the viewport camera:


How can I add color to the hair particle system considering I have a vertex group that it's dedicated on the right side of his head? So, I thought I could assign my vertex group to that material and therefore my particle hair system will react to that behavior. Can someone enlighten me about how to this correctly? My hair is attached to the sculpted head and has 4 vertex groups, right side, left side, scalp, and top (Referring to hair).
I´m using blender 2.91.
Thanks in advance for ur help,

So, the problem with the particle system is that yes, you have to assign in the Particle Properties>Render in the material slot the ''Emitter'' and add another material slot for your sculpture or the other object so it differentiates one from another ''Emitter'' and ''Hair'' respectively.
Note>(Even if you do this with one material slot, that won't work, so in your sculpture put two materials instead of one)
I think the software should make that differentiation from a default perspective, but yeah...Maybe in later versions, they will fix this. I'm using 2.91
How do I make hair particles color independent from emitter?


Linking two armatures into 1 2 models having their own armature,i wish to link both armatures into one ,creating a bone linking both Root bones,making it one armature.

I tried few things,it's ends up messing the mesh.

PS: No constraint.

Select bones of first armature then hold shift and select bones of the second armature and at the end then press ctrl + j. This must be done in object mode. I think this will join two armatures into one.


Why am I only seeing vertices in edit mode? I'm trying to messily get rid of parts of my rough sculpt, but when I enter edit mode, I only see the object's vertices.
Here's what it looks like in object mode:

And here's what it looks like in edit mode:

What's causing this? Thanks in advance!

Update: Fixed it! Apparently all I had to do was show hidden with Alt +  H I'm not sure how exactly I managed to hide only faces in edit mode, but I've resolved the issue regardless.


Can't create a specific displacement based on voronoi texture I'm just messing around with shaders and I can't create an object I have in mind. I have this cube (with subsurface level of 4) and this voronoi texture.

The look I'm trying to achieve is to displace the individual cells, so I get some kind of a jaggedy sphere that exactly matches the cells of texture.
I've tried something like this

But this doesn't work as I thought it would

The problem here that there are multiple colors on one "extruded" column where I'd like to have just one color. Is it possible to achieve this? I'm sorry if it's a noob question, but I'm trying to see what's possible to do with shaders and if I'm expecting too much :)

To save too much strain on the GPU, you may want to separate the business of displacing faces and coloring them, to give the renderer some geometry to work with in the cracks.
You could make a displacement map based on Distance From Edge, shown on the left, below, and a sparate parallel Voronoi to color the displaced faces.

This is a 2D Voronoi, mapped to the surface of the sphere as described here, but the principle would be the same for other cell-like textures


Blender Mesh is deforming when imported into Unity3D So I have a small but rather annoying problem.

In Blender, I've created a very simple rigged mesh so that I can create animations.

In Blender, everything works perfectly. For example I will show a frame from one of my animations where my character puts her hands on her hips.

When I bring this model into Unity3D however, the elbows, knees and chin/head slightly deform into a curve, which is my problem.

Please let me know what you think! Thank you, very much for your time.

Additional information that may help:
I am running Blender 2.76b and Unity 5.3.4f1.
Also, my model has 3 modifiers (Skin, Armature, and Subsurf)

Your model has subsurface modifier applied after the animation deformation which didn't get applied when you exported your model.

So you should apply your subsurface modifier before you export your model.

But,Your subsurface modifier should be at the top of the modifier stack in order to work correctly in Unity as you see it in blender.

So move your subsurface modifier at the top after the skin modifier and apply it.


copy material with python I copy one object in Blender with python。but when I change the old object's color , the new object's color also change. I know that because the new object and the old object have the same material。my way is that：

obj = bpy.data.objects[old_object_name]
mesh = obj.data
new_obj = bpy.data.objects.new(name, mesh)
bpy.context.scene.objects.link(new_obj)
bpy.ops.object.make_single_user(object = True, obdata = True, material = True,texture = True )

I want to Separate the new object's material and the old object's material.when I change one object's color ,another object's color doesn't change. but my way doesn't work.

Material.copy() is what you want. Also you have to duplicate the object's mesh because materials link to the object's data by default.

import bpy

scn = bpy.context.scene
obj = bpy.context.active_object
mat = obj.active_material
mesh = obj.data

dup = bpy.data.objects.new(obj.name, mesh.copy())
dup.active_material = mat.copy()
scn.objects.link(dup)

dup.location.x += 3    # just for clarity


2.8 locking object from selection I want to lock objects from getting selected, but not change their visibility.

2.8 removed the lock button from the outliner. How do you lock objects in 2.8?

The option to make objects not selectable still exists. On the top of the outliner window look for a filter icon (looks like a funnel).
Click on it and you will have access to other restriction toggle switches for the objects in the outliner.


Preview in viewport using OpenGL shader I am trying to apply a custom shader (OpenGL, but if that's not possible I can learn OSL) to a STL. I will not use any lights, cameras, I'm not going to render it eventually. I would like to have the preview in realtime only to see how mesh modifications affect the colors (coming from the shader only) on its surface.

So in practice I want to be able to compute final color value for each and every place on the surface using the shader. Something like this, where you are given coordinates, and the shader computes colors.

The issue I'm having is the multitude of sources: they refer to different Blender versions with different hardware specs, multiple renderers (which apparently changed in Blender 2.8*), BI/BGE, Nodes, Circles, Eeevee, etc. This causes online tutorials to be incompatible with each other.

Without having much experience with it I am trying to find out whether Blender can be used as a inspection/modification tool in such a way as I described above.

Is this doable? How?

You can use viewport draw callback for rendering in the viewport. In your case, I would think of rendering a mesh with a small bias offset over existing meshes to avoid Z-fighting. Then making this mesh semi-transparent with appropriate blending modes to overlay the underlying geometry. Also do not forget to enable depth testing. You can use the GPU module and BGL modules for achieving that.


Applied modifiers are not visible I have an object with two solidify modifiers added, but the modifiers are not visible in the view pane. How can I see the applied modifiers. This is in Blender 2.91

Modifiers are automatic operations that affect an object’s geometry in a non-destructive way. With modifiers, you can perform many effects automatically that would otherwise be too tedious to do manually (such as subdivision surfaces) and without affecting the base geometry of your object.

They work by changing how an object is displayed and rendered, but not the geometry which you can edit directly. You can add several modifiers to a single object to form The Modifier Stack and Apply a modifier if you wish to make its changes permanent.

Apply (Ctrl+A)

Makes the modifier “real”: converts the object’s geometry to match the applied modifier’s results, and deletes the modifier.

Warning

Applying a modifier that is not first in the stack will ignore the stack order (it will be applied as if it was the first one), and may produce undesired results.

(From the Blender Manual)


I clicked on Mirror object but it went to a wrong place Can someone help me wiith this? I need to mirror this "eye" object to the right side < , i select all by pressing A and i clicked on Mirror option , but the object mirrered down and not side as it should be , look:

it should be like this:

And i cant UNDO the item i mirrored because it cannot be selected , i tried crtl z but didnt work too, for so many times i closed blender and opened again thinking i did something wrong , but i dont wanna do it again :S can someone tell me how to undo this too?

After some testings I figure it out - this must be your case, I think.

Before you use any modifier, ever apply transformations.

I rotated my mesh in object mode and applied the mirror and I got a bad mirror.

But after applying the rotation I got the desired mirror.

See the image below:


Blender with Python - Freestyle Linesets I have encountered a problem with Python scripting for Blender.

I have a script which recieves meshes via an external source, and adds them to the scene.
A specific type of mesh is added to the second layer. If such a mesh is created, a second RenderLayer is created and Freestyle-Rendering is activated.
So far, all of this works as I wish.
But I want to add specific Freestyle-Brush-Color to each of this meshes, and so I want to create a Lineset with a linked LineStyle for each one.

Problem now: How can I create and manage the LineSets. I can create a LineSet for the active RenderLayer but without name, and the creation method does not return a handle to that LineSet. How do I cleanly and efficiently retrive the newly created LineSet so that I can add a LineStyle and other settings to it?

My RenderLayer-related code so far:

LineRenderLayer = None
    if not "PolyLineLayer" in bpy.context.scene.render.layers:
        bpy.context.scene.render.use_freestyle = True
        bpy.context.scene.layers = [True] * 2 + [False] * 18
        bpy.context.scene.render.layers["RenderLayer"].layers = \
            [True] + [False]*19
        bpy.ops.scene.freestyle_lineset_remove()
        LineRenderLayer = bpy.context.scene.render.layers.new("PolyLineLayer")
        LineRenderLayer.use_freestyle = True
        LineRenderLayer.layers = [False] + [True] + [False] * 18
    else:
        LineRenderLayer = bpy.context.scene.render.layers["PolyLineLayer"]

    bpy.context.scene.render.layers.active = LineRenderLayer

    bpy.ops.scene.freestyle_lineset_add()

The last line is the main problem. It does not take a name as parameter and does not return anything. But I need that created Lineset for further configuration.

I use Blender in version 2.70

Thank you for your help!

Greetings,
Dragonseel

It is an API design bug that the collection of line sets does not have a .new() and .remove() method.
I will address this problem as soon as possible, preferably in the next Blender 2.71 release.


How do I get the selected object's distance from the camera? I need to precisely visualize one object's distance in order to properly tune 3D sound properties. How can I measure the distance between me (the camera) and said object?

To get the distance between two objects in the scene :

setup a driver with the following settings

type : Scripted Expression
expr : var

add new variable 'var' of type Distance
set the targets to the objects of interest
Now the driver value is the distance between these two object


How do I connect my armatures? I was trying to build a bear skeleton in blender but there are 2 root armatures. How do I fix this? If I try to merge them with ctrl j it does not work and if I try to merge them with alt m it does not work.

Make sure you've selected both Armatures in object mode, and then go to Object > Join


Can i weight paint a logo? Hi i woul like to paint my logo on a weighmap for my grass system but i cant figure out how to change the brush or use a texture like in texture paint mode. Is it nor possible? Should i draw the logo on hand?

Not a direct answer to your question, but you can also use both procedural and image textures to drive the length of your grass:

Hair_Length_by_Image_Texture.blend

More info here.


What are these black lines in my render Not sure what these are but they seem to appear only on certain edges. I've already checked there's no intersecting geometry and all the normals are facing the right way. Does anyone know what these are and how to get rid of them?

The problem comes from your subsurf.
using the "adjust edit cage to modifier result" option will show you a mesh that is not the real mesh. Sometimes it helps but editing without checking the real mesh can be tricky.

In you case you have edge loops overlapping, you'll see it if you disable this option.

you can fix this by moving you edge loop away with GG (edge slide)


how does the RGB curve work? The original documentation was a little less informative so as to fully describe what an RGB curve does. Does it maximize the color of texture? Or, are the x and y coordinates equivalent to input and output level like in Gimp? And how do the seperate channel's curve work out?

Via RGB Curves node (whether Cycles or Compositor) you can adjust contrast, gamma, gain and also offset adjustments. The displayed curve refer to a given color input brightness. The horizontal axis represents the input values, and the vertical axis represents the output values.

Enable C (Composite) to adjust RGB channels simultaneously. Enable R, G, or B if you want to limit the adjustment to a particular color channel.

Also see the manual:

Cycles RGB Curves: https://www.blender.org/manual/render/cycles/nodes/types/color/rgb_curves.html
Composite RGB Curves: https://www.blender.org/manual/compositing/types/color/rgb_curves.html


Can you control material visibility using another object? I don't have any screenshots or reference images, but I'll try my best to describe the effect I mean.
An simplified example of what I am trying to achieve is the following:
There is a target object, and there is a controlling object. Where the controlling object touches the target object, the target surface turns [...],

(this is where the mix shader comes in place, so in an optimal scenario you could insert anything here, such as the target turning transparent or starting to glow)

everywhere else it is black.

I have seen a CG Geek Tutorial on how to achieve a similar effect to what I want, but in the tutorial he uses an object to control a modifier: https://www.youtube.com/watch?v=F13bnOCtYbA
The problem is that there doesn't seem to be a proper way to use weight paint as a factor for materials.

Edit: I figured it out, this is the result I wanted:

I decided to recreate the CG Geek Wireframe transition effect I had been using as reference. Just to avoid confusion: The wireframe look you see in the example is not a modifier but a simple shader using the wireframe node

1. The first step will be setting up the dynamic paint:

Select your target object (in this example: monkey) and set up a dynamic paint canvas in the physics tab. Set the Format to Image Sequence, surface type to "Paint", and enable the Dissolve option with a low time. You can play with the time value and the "slow" option, they basically define how fast the paint is going to disappear.

If we didn't enable dissolving at all, the paint would stay there and the target would stay visible once touched by the brush.

1.1

Next, add in a Brush object. This is the grey cuboid you can see in the example, and the goal is that everything within its volume is visible, while everything outside is invisible. You can theoretically use any mesh, but keep in mind that higher poly stuff might be more performance consuming.

Go to the physics tab and make it a dynamic paint brush object. Set the Paint color to anything, but make sure the alpha is set to 1. The Paint Source should be set to "Mesh Volume" or "Mesh Volume + Proximity", and again, you can play with all of the settings if you don't like what you see.

2. (Optional:) Keyframe/animate your object

This step is only important if you want to make an animation. If you want a still image, skip this.

3. Bake the dynamic paint

Select your canvas (target) object, go to the physics tab and set up the frame count fitting to your animation. If you are doing a single image render, set it to Start:1 End:1 so that it only bakes a single image and doesn't waste your time.
Now scroll down to "output", set up the directory where you want to have the baked paintmaps saved.
UV Unwrap your object and select the UV Map.
Now you can Bake the image Sequence.

4. Shading

Now that you have the paintmap, you can use it as a factor for a mix shader node.
Just add an image texture, select all the images and click open. If you want to have it respond live in the viewport, enable auto refresh.
Add a Texture coordinate node and plug the UV Map output into the Vector input of the image texture.
Add in a Mix Shader Node and Mix two shaders of your liking. In this Example I mixed Transparency ("Invisibility") with Emission. You can use anything else too.
Plug the paintmap into the mix shader factor, and this should be it.


How can I convert Grease Pencil's 'Build' modifier to keyframes? I am completely new to blender and started to learn it for 2D animation purposes.

I experimented with the grease pencil modifier "Build" but I can't figure out how to convert the animated sequence into keyframes.

I would like to have every stroke converted to keyframes in order to adjust the timing of it, remove/add lines etc. Any ideas?

You can divide the various strokes into layers, then add more than a build modifier, targeting each one to a single layer. Then every build modifier can be set to start at one certain frame and last for any number of frames.


Rename a modifier's name for multiple objects I have multiple objects and they have the same exact modifier with same name (same parameters , name etc). For example :

cube1 has modifiers : array1, boolean1
sphere1 has modifiers : solidify1, boolean1
cone1 has modifiers : boolean1

So i want to change the name of boolean1 to become myboolean for multiple objects at once. Can i do this ?
Do we need python for this ? using Alt doesn't do the trick for multiple edit.
Thanks

Iterate over all objects (or all selected objects, in the following script). If the object supports modifiers, check if the looked for modifier name exists, if it does, rename it.
import bpy

previous_name_modifier = "boolean1"
new_name_modifier = "MyBoolean"

for obj in bpy.context.selected_objects:
    if not obj.modifiers:
        continue
    mod = obj.modifiers.get(previous_name_modifier)
    if mod:
        mod.name = new_name_modifier


Is there any way to modify transform widget thickness? is possible to tweak transform tool's thickness?

if you mean to change the gizmo size you can do it through Preferences --> Viewport --> Gizmo Size


My AMD GPU is not available in Cycle Render Preferences on version 2.8 I am using laptop with AMD Radeon HD 8670m GPU in it. I have latest drivers installed. But when I access Blender System Preferences it displays:

"NO COMPATIBLE GPU'S FOUND. CYCLES WILL RENDER IN CPU".

I used the same in 2.79 and I found  no problems. Please help me fix this issue. Thanks in advance.

Your graphics card doesn't meet the requirements for GPU rendering with Cycles as @DuaneDibbley already linked. The minimum requirements for the GPU are only for being able to run Blender at all.

For Blender 2.8 you will need GCN first generation or newer to run Blender. GCN second generation or newer is required for OpenCL GPU rendering.


How to create segment a large model of landscape into smaller sections that can be higher resolution? I hope to make a 3D model of existing landscapes in blender, with the hope of eventually adding them to video games that allow you to create your own maps. I tried using the following two tutorials with no luck: https://youtu.be/BXDSfrzR0zI and https://www.beamng.com/threads/tutorial-level-building-with-lidar.39370/

With the video, I do have 3D maps, but I think I have too large an area with too low of a resolution. This is because when I try to zoom in, it seems the roads are a bit blurry. I am trying to start out with somewhat large areas, like the island of Nusa Tenggara Timur in Indonesia, with the hopes of slicing out a smaller section that can be used in a game without crashing. I am quite new to blender and while I can follow along the video tutorial, I’m not 100% understanding everything I’m doing and what the alternatives are.

To answer your question. Slice down your original hight map into smaller parts. So you can assemble multiple so called map tiles into one high resolution map.

For large detailed enviroment usualy tiling maps are used in game engines. The heightmaps are loaded directly in a shader - in modern games with adaptive generation of geometry depending on the distance you can actualy see (Tesselation).
If you generate a high resolution mesh for each map tile you most likeley will run into memory issues.


What do the modal operators do? What do the modal operators do? They are found below the 'Border Select.' Why are there so many of them?

If I  assigned a HotKey to 'Border Select' as shown in the screenshot, what values should I put in modal operators, to 'Border Select' work as Deselect geometry through Alt + Left mouse?

So I need need to left-click + drag mouse Select geometry (or part geometry) and
  Left-click + drag mouse + holding Alt  Deselect geometry (or part geometry).

A modal operator is just an operator that does things a little differently. While there are tons of ways to setup a modal operator, it doesn't have quite the same clearly defined lifetime like regular operators. For example, if you wanted to move an object with a regular operator, the implementation would do something like this the following and would execute in a fraction of a second.

Get how far you want to move it
Move it
Quit, and return what happened (success, cancelled, etc.)

On the other hand, a modal operator that does the same thing has a completely different functionality. It may take a very long time before the user has confirmed the motion and stopped the execution, but Blender shouldn't become unresponsive if it is written correctly.

Start the modal operator
Interact with the user in real-time to update the position
Stop (generally when the user ends the process) at some point and return the results

However, not all modal operators take over all user interaction like you may think. For example, you can have a modal operator that is always running and displays a clock in the 3D viewport. You could have an operator that shows the bounding box and wireframe for selected objects.

Here is an example of a modal operator that does both of the above.

So the real answer to What do the modal operators do? is simply an operator that runs in the background.

The Blender Python docs put it this way:

  This operator defines a Operator.modal function which running,
  handling events until it returns {'FINISHED'} or {'CANCELLED'}.

  Grab, Rotate, Scale and Fly-Mode are examples of modal operators. They
  are especially useful for interactive tools, your operator can have
  its own state where keys toggle options as the operator runs.

Here is a useful post by one of the Blender developers about all of the "operator methods" including modal:

https://blender.stackexchange.com/a/19431/28015


What setting do I need to be in to see colour? I am new to Blender, been following Blender Guru videos... suddenly I can't see colour and I am really struggling with controlling the camera. I must have hit the wrong button...
He moves too fast for me to follow what he is clicking on often.
I guess my question is really... is it normal to watch videos 8-10 times and still be lost?

I think everyone struggles a bit in the start. Just persist and keep watching his videos. I would also try Grant Abbit. He does a very good job of explaining the things and has lot's of videos for intermediate and beginners. For your colour question there is a screenshot of colour management in blender. Make sure that the settings are set to what I have here.


How do I get this rainbow to fade and disappear? I'm very new to Blender. I had wanted to learn it some day and my young daughter has decided to make a TV show, so I guess that time is now.
I'm using version 2.91 and working in 2D. The rainbow is a Grease Pencil object and the cats are imported images. In this scene, the rainbow is supposed to disappear, leaving the cats to fall down to the ground. I finally managed to work out how to assign opacity values to different keyframes, but instead of fading to transparency, they fade to white and I can't work out why. What am I doing wrong?

Me too a beginner and me also don't know much about 2d animation but I think I figured out how to do it.
After drawing the rainbow chose the frame you want the rainbow to see, then go to object data properties and make sure that opacity is at 1.000 (1). Then move your mouse pointer to the opacity and click 'I' you can see that the opacity tab is now yellow. Then chose the frame that it want to be completely disappear. Make the opacity to 0 and click 'I'. Press space bar and see it fades away.


Visible seam on the mesh I have started to model a torso. I was happy with it, until I discovered the seam in the mid of the mesh. I have not used the mirror modifier at all, what else could it be?

It seems that half of the normals in your model are inverted (the normals of some faces are facing inward and some outward). This might be causing display problems.

Go to Edit Mode, select all faces and use CTRL + N to recalculate normals.

If recalculating the normals doesn't help, display face normals as lines, select only the faces with normals facing inward, and flip normals on those faces.


Reflective material don't reflect a mesh I am quite new to Blender. I tried to set up a scene with a little character I modelised with a floor and an hdr. My problem is that the parts of my character which has a reflective material reflect the hdr but not the floor.
Here is my viewport with viewport shading. I use eevee.

You need to go to the render properties >>> Screen space reflections


CUDA error at cuCtxCreate : unknown error os : Pop!OS
ver : Blender 2.81
device : nVidia GeForce GTX 1080ti

every time my computer falls asleep with blender open, when i try to get back to my work i get this error and blender can't find any CUDA devices when i try to turn it off and on again. this seems to be fixable only with a system reboot but i'm hoping there is a better way. Has anybody experienced this issue and has a way to fix it ?

some additional info - i had the same problem using older versions of Blender and this would also happen under ArchLinux

I had this issue before when rendering an animation.
The solution is to simply decrease the tile size under performance.


How can I control node values without input inside a group node? I have created the node group, but I can't control the values inside.

This issue was discussed in Controlling ColorRamp nodes with Group Inputs post but as Blender workflow get simplified and I wasn't able to find this post druging googling I decided to add another answer.

Right click on source and choose "copy as New Driver" then go to the target and "Paste Driver". You can use any group node silder as a Driver.


How To Un-Twist a Spiral STL Object? I have a cylinder-like spiral object as .STL file. There are edges responsible for being twisted (Highlighted in the image below). How can I un-twist it partially (or fully, so that I'd have a flat surface at the end)?

Edit:
What we want finally:
Compressed (left) vs Stretched (right)

The mesh is very messy so you can't really expect any tool to do a good job here. You can try Limited Dissolve (X-menu) and adjust the Angle and see if that works.
Otherwise it might be faster to remodel it.