Distorted exported .fbx model when objects are under parent This is the model I am trying to export to FBX:

I consists of leaves (named "Leaf.001" - "Leaf.006") that are linked duplicates of an original leaf (named "Leaf") created from a plane mesh, and a twig created from a cube mesh.

The problem is if I make the Twig the parent of any of the leaves (in the following case, "Leaf.001" - "Leaf.006") and export the model as a .fbx file, re-importing the file gives me a distorted model:

This problem doesn't occur for leaf models left in the root hierarchy.

The same distortion occurs if I import my .blend file into Unity.

I think it has to do with the leaf meshes, because the distortion doesn't happen for Twig objects children to a Sprig (subdivided cylinder), and Sprigs children to a branch (beveled bezier curve), and so on.

I'm not sure if this problem has been resolved or not, but for future reference, I also frequently work with Unity and when FBX exports are distorting for me, it usually involves one of two things:

1) As mentioned in comments, I have a mesh that has an unapplied transform to it, and the FBX exporter is getting confused.

2) I have an animation doing something wonky on its first keyframe, which needs to be replaced or removed. This can result in distortions which look nothing like the animation itself, particularly if there was unapplied scaling or rotation involved at some point.

This may or may not solve the issue, but I'd bet that it's an animation. Perhaps the model has an entry for the leaves rustling or blowing with the wind?


Noob - world color affecting rendered (plane) image Just started with Blender yesterday, and already loving it.

Here's the blend I created mostly with a couple of youtube tuts. A simple PNG with transparancey, and a camera that tracks along a path while looking at the logo. http://simonandrewsphotography.com/db/index.php/s/ZqXFKXijql4odRj

Before rendering, everything looks fine, the logo text is purple. My problem is after it's rendered. When I set the world surface (world>surface>color) to orange (#FC7919), the purple text becomes a deep red. If I set the world surface color to white it's fine.

I'd also like to blend 2 shades of orange to make the background a little less boring.

The reason for this is that the world color does not only define the background, but also acts as a light source. When you set it to orange, you have a purple object illuminated with orange light, causing the red end result.
Using the white world color will illuminate it with white light, allowing the object to stay purple.

You could have a look here for a method to use a white lighting while having a colored background.

I've uploaded an example. The only changes I made that aren't directly visible when you open the file is that I enabled "Transparent" in the Film tab under the Render panel.


What does "self lit" mean, and why is it a good thing? I've seen some artists post scenes they describe as "self lit" [1],[2]. What does this mean, and why is it desirable?

It refers to models that already have the lights prebaked using lightmaps or pre-render all the model and bake it into a texture. Both are useful for real-time visualization of static scenes, since it can show photorrealistic results without have to render everything everytime. You can get more information about in the links below:

Lightmap: https://en.wikipedia.org/wiki/Lightmap

Baking: https://www.youtube.com/watch?v=sB09T--_ZvU


Why i cant make yellow bright I have my mesh and its pale yellow i want to make much bright yellow. In the nodes its bright yellow but render it looks pale yellow. What extra nodes should i add to get a bright yellow. Any suggestion or help. Thanks

Nodes :

Pale yellow

Need this type of bright yellow

I'm not sure why you have the Layer Weight node ("TransFresnel") but my understanding is that the Layer Weight does not have any practical use when used for volumetrics - it should only be used for Surface shaders. In addition, using different densities for the Scatter and Absorption can cause unpredictable (and non-real-world) effects - and typically the Scatter and Absorption shaders should use the same colour or, again, this can cause unexpected results. Therefore, I'd suggest the following material :

Note how the RGB node feeds into both volumetric shaders so that the same colour is used for each. This is in place of the Layer Weight node in your set up. Also note the use of a single Value node to control both densities so that the shaders are consistent with each other.

Note also the Volume Bounces at the right-hand side of the image. This defaults to zero which would mean that rays are not permitted to bounce multiple times within the volume as they scatter, causing the light to never reach the camera (making it darker). You should increase the number of bounces to, say, 3 or 4 and this should make the material absorb less light.

The above example was based on the default cube with the only changes the material, brightening the default lamp from 100 to 1000, and increasing the Volume Bounces to 4 and reduced Volume Sampling Step Size from 0.1 to 0.025 to increase the volumetric quality.


Is there a way to change the mortar color of an image texture from black to white through node editor? Newbie Question:
Below is an image texture of a brick wall with a black mortar:

Using node editor, is there a way to change the black mortar to white without changing the original color of the wall?

You can use a setup similar to this answer.
Since the target color is black, you can calculate the relative length of each channel, use a Math node set to "Less than" and tweak the threshold to mask the grout part.
Then use a Mix RGB set to Mix to set the grout color (here, white)

Result :

Since the grout is not pure black, you have to tweak the Compare node threshold to get the desired effect. Too little, and you have persisting black spots. Too high, and you begin masking undesired darker colors.


How do I make a pulsating light effect material? I wanna make a material or animation that can do something similar to this video on multiple different points on a surface. But with different speeds and distortions.
https://www.youtube.com/watch?v=Sj0NEtvvUZ8

At first I tried selecting an area of faces, create a vertex group, select a wider area of faces, create a new vertex group and repeat that a few times. Then I tried to plug in the vertex group into the vertex group field of the wireframe modifer and animate it. With all the vertex groups animated together, I was hoping to get a pulsating effect. But when I keyframe a new vertex group, the last one always gets overwritten for some reason.
I also tried to see if I could do something with the mapping node in the video below, but can't get anything that I'm imagining.
https://youtu.be/5_4lNC0JXW4
Can anyone help with this?

A pure-shader option, for use on a simple plane, or any surface:

The top branch wraps the circumference into segments, using a Gradient > Radial node. The wrap is controlled by 'n Spokes' input.
The middle-ish branch wraps the radius into rings, by length from the object origin. The wrap is controlled by 'n Rings' input.
There are quite a few 'convenience' nodes in there, so the user doesn't have to fish around for tiny numbers, and to put 0 at the middle of each cell the plane is divided into, when the circumference-wrap and the radius-wrap are combined to give a per-cell X and Y.
The bottom branch splits the radius into color-bands, with an extra bit to dim the center to pure black, if you want to.

This sort of result:

I guess there's a limitation here.. the dots are not perfectly round. The 'Roundness' input fudges that. But they aren't round in your reference, either.
The effect is animated by keyframing the 'Phase' input.


How to import a .mtl file? I am new to Blender. I downloaded a .obj file of a plant model. When I unzipped it I found two files (.obj and .mtl).
I imported the .obj file and I couldn't do the same with the .mtl to apply the material and the textures.

When you import the .obj file, Blender will also import the associated .mtl file* by default as well which is usually the same name. The colors applied to the model will show in the viewport and to see the texture(s) (if any), enable texture shading with AltZ.

* This is the file that should be generated alongside the obj when it was created and will hold color data and paths to textures if any. Opening the obj file in a text editor should show this near the top.


Pyramid that cannot 3d print because its different in Blender / print software I have remade my pyramid in blender 4 times now, becoming an expert, but my pyramid has the top cut off, it is a hollow pyramid with the top cut off

When I load it into the STL format, Blender saves the whole pyramid, including its GHOST top when there are no visible vertices or edges too allow the top too exist.

every 3model you want to 3D print should be closed (watertight), so your piramid should have thick walls, and not single layer faces. That would solve your ghost tip problem as well


Is there a shortcut to switch between Add and Subtract brushes, in Sculpt mode? I'm working on some sculpting but I hate that I have to go to the Toolshelf and select Subtract, whenever I need that brush. So, while in Sculpt mode, how can I switch between Add and Subtract brush modes, with a shortcut?

You can press and hold Ctrl to toggle between sculpt modes. While pressed you will be in the opposite mode to what is selected in the toolshelf; i.e. if you have selected Add, then while pressing Ctrl you will be in Subtract Mode.

A list of all keyboard shortcuts available in Sculpt Mode.


How to connect the mirrored bone to the central bone? I appended a suffix of .L to the name of a bone on one side, then executed armature -> symmetrize to mirror the bones.

However, the copied bone is not connected to the central spine, and if rotated in pose mode it will move away from the spine.

How can I make the copied bone connect to the backbone?

After activating connected in edit mode, the bones are connected.


Modeling rockers (Rocker rail's) for a chair I'm trying to figure out how to make the edges on the rockers (Rocker rail's) round without affecting anything else as shown in the reference photo

You can use proportional editing for the round ends and Simple Deform for the bent shape.

Use proportional editing with Sphere faloff for the ends.

Use Simple Deform modifier set to Bend for the bent shape


Concave Square with Straight Sides I am currently attempting to recreate the new Xbox Series X console within Blender, but am stuck on the top of the console as shown here:
The console has a very nice concave surface on the top while still keeping the edges square and flat.

I have attempted using proportional editing to no avail (exaggerated to show issue):
The surfaces near the corners are completely flat and should be bending slightly.

The bool tool with a sphere yields curved sides.

What would be a good way of recreating this complex curve?

This can be accomplished by using proportional editing.

Add a cube.

Switch to edit mode (Tab) and subdivide it (F3 > Subdivide). Use an odd number of subdivisions in order to have a single vertex at the center of the cube face. Use a low number of subdivisions, e.g. 5.

Select that single vertex at the center and enable proportional editing (O) and set the falloff type to Sphere.

Move the vertex down on the z-axis (G + Z). If you're not using the default dimensions of the cube you may have to adjust the radius using the scroll wheel of your mouse. The outer edges of the cube shouldn't be within the radius of the proportional editing.


Can I color a curve in BI by the direction it's running? I recently asked the same question for Cycles, but now I'm curious about the pros/cons of using Blender Render instead - can a curve's tangent be used to define the color of its beveled/tessellated output mesh?

While not used very often, Blender Internal has support for node based materials. Almost the same node setup can be re-created in BI by changing the emission for a material node and the one missing being the Tangent node. While not the same result, the Global output of the Geometry node gives a similar effect. If you wanted a matching result between the two you could use Object output from the Texture Coordinates in cycles to get the same result or with some extra math nodes you may be able to get the BI nodes to give the same result as the cycles tangent node.


Partially disable File Output Node in compositing? A File Output node like this ...

... will generate several images at once (here: A001.png, ..., A250.png and B001.png, ..., B250.png and C001.png, ..., C250.png, all in folder D).
For reasons involving different render border settings, I would like to sometimes only render A and B, say, sometimes B and C, sometimes only A, and so on.

Q: Is there a way to "elegantly" switch off generation of individual outputs (I think they are called subpaths)? The only way I have found so far is to disconnect the individual inputs. In order to facilitate disconnecting and reconnecting, I already added reroute nodes nearby. More "elegant" would be a checkbox or the like (perhaps even animate-able)

If you output to multiple png files, there is no downside to having separate File Output node for each instead of the one with many inputs. You can then select the ones you want to temporarily disable and press m for mute. If you had multilayer EXR that would be a problem, but since you only need to output separate PNGs, that should work fine. Disconnecting inputs also seems elegant enough for me.

You can also use this new node Switch (Blender 2.80) that you can find in Add -> Layout -> Switch

It gives you a checkbox and you can hit ctrl+h to hide unused inputs when you have it selected as you can see I have done on the first one for it to be more compact. It seems to be animate-able, but I have not tested it.


Toon Style Explosion I want to make toon style Explosion similar to that which is given below:

A simple setup for material would be helpful. References:

Somethink like this ? (Using similar, not same teqniques?)

https://www.youtube.com/watch?v=3XZjhESZPxA

At the firs place, its not my tutorial, originally its from Pierrick Picaut
and his P2Design. Also you can download whole tutorial from official https://gumroad.com/l/Stylised-explosion-blender for free.

And how he made it ?

The explosion is created by animated mesh with various noise displacement and animated parameters. You can use particle system with noisy-spheres like the mesh also.

For material Pierrick used MatCaps, with right outline setting for smoke, but you can use whatever you like if you get right fresnel-like faced soft outline.

For the exact explosion he used Color ramp and emmission node like this:

This system of material can be used for every toon-like visual, you can use every color you want, or mix with other properties like noises or lights.

So after all if you want change the smoke from shiny yellow-red color to calssic grey smoke Pierrick used Mix node and he animated fac property with greater then mathematical node.

From there is the same steps for every part of explosion. But you can use transparency node instead color ramp at the second input in mix node, so you will get only kinf of outlines for the details.


Sine wave function as an input value? It is possible to use the variable #frame in an input field to make the value increment with each frame. It behaves as a Driver.

Example:

We can also halve or double the rate using #frame/2 or #frame*2 respectively. So I got to wondering to what extent we can write expressions in input fields. How complex can we get?

Is it also possible to input a sine wave as an expression?

The purpose would be for quickly animating objects that move cyclically:

Sure, why not. The # symbol in the input field tells blender that you are inserting scripted driver with no variables. Everything after # will be put into the driver's expression field.

You can get a list what functions are build-in by typing bpy.app.driver_namespace[' into the console and hitting CtrlSpace.

You can totally input #cos(frame*pi/20) to match the curve you provided in the question.


Blender Cycles - Alpha Over Node - How to get a combination of two layers and get as result something like 1 layer over the other? Maybe the title is hard to understand so I explain quickly. I have 2 layers, one with a flat text and the other one with the outline of the text (freestyle). If I combine both (with Alpha Over) the resulting image is not the same as if I render on the same layer text plus the contour. It seems like the outline is less "strong" when I'm combining the layers in comparison with a direct render of object + contour.

As it can be seen on the image (on a subtle way) on the combination between layers, the stroke is a little bit less strong as the full render. How do I do to get exactly the same result as the full render when I combine two layers?

Thanks,
Gonzalo

It's because Alpha Over takes transparency into account. Composite using Z-Combine node instead. You connect Render Layers' Color and Z directly to the node.


Is it possible to have automatic LOD (level of detail) on large scenes? Objective: build a virtual suburb in blender for use in creating exterior shots (not realtime: shots will be rendered in Cycles).

The angles of these shots will not be known in advance, so it's impossible to guess in advance which elements need to be high detail and which can be low detail.

Large scene becomes unwieldy and incredibly memory-intensive with hundreds or even thousands of high-detail objects, especially when many are not in shot. Scene will be utilized by an artist on home computer, so excessive memory use is not viable. Convenience is the primary objective to maximize efficiency in setting up and rendering shots. Renderer to be used is Cycles.

The higher detail of the nearby models would not necessarily be provided by subdivision. A perfect example of the sorts of things I'd be working with are buildings; up close, they would have fully modeled doors, windows, and other small details like flags, while far away, those fine details could be baked into textures, made more rudimentary, or simply omitted altogether.

Is it possible to automatically swap out lower detail meshes/materials at long distance for these renders?

I am also interested in alternate solutions. Since there are only 20 layers available, the only alternate solution I can come up with would be to divide the suburb into sections and have a high-detail and low-detail version of each section put onto adjacent layers, which the artist will toggle based on the position of the camera and what is visible in the shot, but this would be less than optimal. Any other ideas are welcome.

I have two pretty detailed posts that when added together, would seem to come up with a pretty good fit for your situation.

I won't detail out those steps, but I will link to them, and summarize the workflow in a summary of logic.

Creating Distance/Rotation/Scale Based Drivers - See this post

Swapping Groups of meshes with drivers - See this post

The main rundown here, would be to drive your level of detail threshold by camera distance values, then using the same logic of swapping groups of meshes, use this threshold value to determine which LOD group to select on any given instance with this driver attached.


How do I bring back the orbit gizmo in the top right of the viewport? I've been looking this up for a while now, I'm new to blender. I've been working on a project for a while now in 2.8 and I'm pretty sure I hit some shortcut but in that specific save file in the layout workspace the orbit gizmo you use to easily swap orthographic perspectives disappeared, it seems like some random shortcut that I pressed when trying to recall a different one. ctrl-space is not working and load factory setting loses all my work the modeling workspace is unaffected so I could probably change that around to get a similar workspace without the problem but it would be better to know what's causing the problem so I don't do it again.

The Navigate gizmo can be enabled in the overlay menu.
And all gizmos can be (accidentally) disabled through Ctrl + `


How to create cotton wool? How do you make cotton balls fluffy with perhaps some loose bits hanging.

I've tried this, I think it needs more hair work though, to get the fluffy thing. For the material, I've used a Noise Texture that I've scaled on one axis to get the stria effect. Emission is here to give a bit of luminosity and softness to the object, too much shadow would make it look solid like a stone, it somehow simulates a transparent effect. And at the end a bit of Transparency, with a Fresnel as factor, to make the contour a bit evanescent. The hairs are actually long extruded rectangles with a material that also use a mix of Diffuse, Emission and Transparency.


Increase Ambient Occlusion Effect So ive been trying to figure out how to do this in blender for the last 2 days now and got no where.

I want to increase the effect of ambient occlusion when i bake it onto a texture.

I achieved this(right monkey head) by ticking the ambient occlusion box in that side panel and adjusting the settings but couldn't figure out how to bake this into a texture :/

As you can probably tell im not that great with blender. As a programmer, blender is turning into a bit of a night mare since everything i want to do seems straight forward but turns out is isnt at all

Any help would be greatly appreciated.
Thanks ~Scott

This is a basic setup of environment lighting (with lots of AO) in BI:

To bake out the AO, just go to the bake panel and select to bake AO...

Of course, you need to do the usual bake stuff for BI (UV unwrap to a valid texture, etc.).

Here are some links for BI:

How do you bake ambient occlusion for a model?

https://docs.blender.org/manual/en/dev/render/blender_render/bake.html#ambient-occlusion

https://docs.blender.org/manual/en/dev/render/blender_render/world/ambient_occlusion.html

https://docs.blender.org/manual/en/dev/render/blender_render/world/ambient_light.html

And for Cycles:

http://www.blenderguru.com/tutorials/introduction-baking-cycles/

Here is my demo blend file (post all blend files on this site BTW):


Controlling a text object through python. Hooking it to an internal variable Okay so I'm using a text object eventually odd like to make it into a health counter. My code is sloppy though and needs refining.

Here is what I got.

import bge
from bge import logic

cont = logic.getCurrentController()
own = cont.owner
scene = logic.getCurrentScene()
T = scene.objects['Text']
z = cont.sensors['z']

if z.positive:
    T ['x'] += 1

if T ['x']  == 0:
    T.text = 'failure'

if T ['x']  == 1:
    T.text = 'success'

if T ['x']  == 3:
    T.text = T['x']

The last line didn't work, the money says that it returns without exception set. This is just a test to find something that sort of works. But ideally I'd like the texts to simply display a variable as it changed. Z is a keyboard sensor and x is a property linked to the text. Can someone tell me how I can just get the text to display the integer property x?

Also being able to reference the lines in a text file for text would be great but if that's to much to ask then please just help me with the first one.

When trying to execute your code, I get the error:

KX_GameObject, key "x" does not exist

Replace all your T['x'] with another objects property such as:

T.localPosition.x

If this isn't the property you want, you can search the objects fields with:

print(dir(T))

You have to parse/cast the int to a string with the python str() method.
The last line compiles fine as:

if T.localPosition.x  == 3:
    T.text = str(T.localPosition.x)


eGPU Vega 56 (Blackmagic) Mac + cycles problem Hello I just got the AMD Radeon RX Vega 56 (blackmagic eGPU Pro) yesterday
plugged it in to my brand new Mac mini (Mojave), it shows up in the menubar and as an alternative as a render engine,. My question is, can I use this eGPU for cycles renders? (Blender 2.80)

Very grateful for your responses.

You won't be able to use GPU rendering with Cycles. Apple has deprecated OpenCL for macOS 10.14 and future releases. Since macOS won't have any updates for the OpenCL compiler and therefore no bug fixes, Blender 2.80 will no longer use OpenCL on macOS. This was originally announced on the bf-committers mailing list by Sergey Sharybin. It is also documented in the manual and the release notes of Blender 2.80.

AMD OpenCL
OpenCL is supported for GPU rendering with AMD graphics cards. Blender Supports graphics cards with GCN generation 2 and above. To make sure your GPU is supported, see the list of GCN generations with the GCN generation and supported graphics cards.
AMD OpenCL GPU rendering is supported on Windows and Linux, but not on macOS.

A third-party render engine that supports the Metal API may work, for instance AMD Radeon™ ProRender.


Accidentally deleted nodes in compositing tab. Can't recover it? I accidentally deleted the 'Render Layer' and 'Composite' Node. I panicked and didn't know what to do, so I thought maybe if I close my file, itll come back when i open it again. So I closed my file, and obviously saved it because it had all my progress, but my dumb self didn't think through that it might save the action of deleted nodes as well.
I have tried everything to reverse this but nothing works. I tried manually adding these nodes. I do get the composite node fine, but the 'Render Layer' has missing bits.
I even uninstalled and re-installed Blender to fix this, but nothing.
I have attached images with the original 'Render Layer' node and the one I'm getting now (which doesn't have all the properties that I need).

Link: https://imgur.com/a/TbqOxJ4
TLDR;
Accidentally deleted 'Render Layer' and 'Composite' Nodes. Can't recover them no matter what I do. Manually added nodes have missing properties.

Do not worry, this looks easy to fix, even if this diagnosis is wrong.
The image looks like render passes that were previously enabled have been turned off, and thus aren't showing up in the render layer node. Check this manual page for information on render passes. https://docs.blender.org/manual/en/dev/render/layers/passes.html


Animating the camera's focus during a render with motion blur From another perspective: "Focus tracking during exposure"

OK, so this is probably pretty obscure, but it looks like the motion blur system in cycles isn't taking into account camera focus over time.

[EDIT] Just to clarify, I'm using motion blur to refer to the renderer integrating over time. I'm not asking about an image space selective blur or approximation, but a physically accurate render and effect.

I haven't had any luck with either setting a moving object for focus tracking or setting keyframes in the distance field. In both cases focus does change correctly when moving between each frame, just not in a render with motion blur.

Attempting to focus track a moving cube (with a static one for reference):

Is there something I'm doing wrong or is this on the todo list?

[EDIT]
In regard to what this might be used for:

Case 1. You actually want to integrate objects transitioning out of/in to focus such as in this photo: Fireworks refocused quickly during an explosion

There may be none or little actual movement for the motion blur but changing focus during an exposure can add interesting effects. Here, I'm use the name motion blur to refer to integrating over time which is what the effect actually does, rather than literal blur from motion.
Case 2. You have a shallow depth of field (and still want the effect that gives), but you want motion blur of a subject moving perpendicular to the focal plane without the defocusing effects of Case 1. Tracking the moving object (with focus only and the camera remaining stationary) would give this effect. In doing so the background will not be blurry from motion, but may change focus a little.

Motion blur is separate from Depth of field (camera blur). The object will only be more in focus if either the motion blur is turned down or there is less movement of the object relative to the camera.


Why doesn't constraining to a vertex group behave like parenting to vertices? It is possible to constrain objects or bones to vertex groups using Child Of, copy rotation, etc. However, when you do this, you tend to get odd behavior, especially with bones. They tend to roll over or otherwise flip strangely.

However, if you parent an empty to 3 vertices, it works reliably. You can then constrain the bone to the empty. But this is a lot more setup.

Can anyone explain why these behave differently? Why is constraining directly to vertex groups not viable, and is there a way to solve it? I remember reading about it somewhere in detail a year or two ago, but cannot find it now.

When using a "Child Of" constraint with the vertex group option, because there can be any number of vertices, the rotation must be derived from a mix of all the vertex normals.

Even if you just use 3 vertices in the vertex group, the normals of those three vertices will be affected by other vertices that are not part of the vertex group. If those three vertices are connected by edges to other vertices, the connected vertices will affect their normals.

When doing a vertex parent, there is a guarantee of only three vertices so the algorithm is a simple barycentric algorithm.

If you make a duplicate of the three vertices in your group and detach them from other vertices you should get the same behavior with a "Child Of" constraint that you would get with parenting to three vertices.

One possible workaround would be to duplicate the vertices you want to use with the constraint so they are not connected to any neighboring verts that could affect their normals. You could delete their faces so they don't show up in render. I tried the mask modifier but it kills the constraint.


Rotate bmesh around Vector with Python I try to rotate a bmesh around a vector as axis.

vec = vert1.co + vert2.co
rot = mathutils.Euler(vec/max(vec)).to_matrix()
bmesh.ops.rotate(bm, cent=vert2.co, matrix=rot, verts=bm.verts, space=objCT.matrix_world)

But unfortunately it rotates in a strange way. How could I fix this?

Rotate bmesh vertices around a vector defined by two selected verts.

Test script, rotates 45 degrees around the vector defined by two selected verts.  Select two vertices and run script. Running 8 times should rotate the full sweep.

import bpy
import bmesh
context = bpy.context
from mathutils import Matrix
from math import radians

obj = context.edit_object
me = obj.data
bm = bmesh.from_edit_mesh(me)

# have 2 verts selected.
v1, v2, *_ = (v for v in bm.verts if v.select)
axis = (v2.co - v1.co).normalized()
rot = Matrix.Rotation(radians(45), 4, axis)
bmesh.ops.rotate(bm, cent=v2.co, matrix=rot, verts=bm.verts)

me.update()

Note: because our rotation matrix is using an axis and both v1 and v2 are on the axis,  either (or any point on) can be used for cent property of operator .  The centre point would be calculated via v1.co + axis / 2 or (v1.co + v2.co) / 2


UV coordinates on a deformed plane I added a plane to a scene, subdivided it, and deformed it with proportional editing:

I'd like to UV unwrap this plane, making the mapping what the would have been without the edit mode deformations. In other words, I'd like my UV map to look like a square grid.

Is it possible to UV map this deformed plane to a square grid? Or do I need to start from scratch, and make sure I unwrap it before I do the edits?

It is simple to unwrap a deformed plane like in your image, back to a square UV map.

In face select mode, select all the faces with A and make one of the faces active.
Then press U > Follow Active Quads and then choose Even and press OK.

This will give you a even square UV layout.


cannot get rigify rig to bind to mesh I am trying to animate a pony. I have a bunch of weight groups for fur. I am trying to bind the rigify rig to the mesh just to make sure that everything is working before I move on into more advanced rigging setups for inverse kinematics and xmuscle systems. However, I cannot get the rig to bind with with the mesh, nor can I get the bones to bind with the mesh. Here is a link to the file if anyone can figure it out. I would greatly appreciate it!

https://www.dropbox.com/s/cjkv4yr6dkjk3it/test.blend?dl=0

I checked it, first problem, you have your rig parented manually with your mesh, when you try to use "Parent with empty or automatic weights (or other algorithm) you have to have your mesh and armature without any parent/child relation, so you have to delete the parenting.
Now you will be able to parent your mesh to your armature (first select your mesh, then your armature and use parent) manually painting the vertex, only manually, why? Because you have duplicated vertexes and non-manifold topology.
If you want to use automatic weight paint you have to clean your mesh first.

Any further questions, don't hesitate to ask me.


How to keep logic bricks organized? When I make something in logic bricks, I try to have everything always neat. I always end up with a lot of bricks that lead to a brick way upwards and/or way downwards. When I make edits, I would usually erase everything and start again. I would like to organize this in any way. Is there a way you can put a little divider to just store a certain function? This way, when I start a new function, everything would be leveled. Is there a plugin for this if this does not exist? I know you can do this in programming in just about every language. Any help is appreciated, thanks!

EDIT: I have been given a question that, in some ways, can be seen as a duplicate. I am not looking to have my logic bricks behind the scene, by unselecting the link button. I am looking to have layers of logic organized by what can be a divider; this feature is most likely not in the engine, so I am probably looking at an addon.

Organizing with states

You can use the states of the build-in state machine to group your bricks.

This allows to quickly show/hide/switch logical groups. You can do that by selecting/deselecting states in the visible-state-bar.

Requirements

Make sure all states with logic are enabled in the initial-state-bar.

Example

This way you can group this logic:

into movement logic:

using logic by keyboard

and using logic by mouse

Hints

You do not need to use the state machine operations (state
switching).
You can select multiple states at the same time by
holding  when selecting/deselecting a state.
If you need more than the 30 available states I think it is time to review your design. Most-likely this object simply does too much. It would be better to spread the logic over multiple objects.


Checker deselect doesn't seems to work properly Here is a primitive cylinder 32 sides, when I try to make a checker deselect it seems to not be deselecting properly, as you can see in the example where I have to manually correct things to have a proper 8 edge deselection.
Does anyone have a solution to do it automatically ? Even the 3 edge deselection seems buggy and leave an undesired gap

.

In my limited experience of this tool, it does not seem to work reliably on loops when your deselected & selected are not 1, 1. i.e. a checker board.  Any other combinations may result in gaps. I can't checker deselect a face loop around a default sphere, with a setting of 2, 2 without a gap of 1 or 3 appearing, although there is no reason why it shouldn't work. The same goes for edge selections.
Selecting an even number of faces or edges on a subdivided plane, the side of a sphere or a subdivided cylinder does work as expected.
The combination of Deselected and Selected should logically fit into the number of elements the object has. You have 8 and 1, adding up to 9, but your shape has diagonal rows with around 12 or 13 faces per diagonal.
You have chosen the most confusing image possible to illustrate your point. It might have helped if you had used a solid view, and a more regular shape to show the problem.


The colors that I get in Python directly from the nodes are darker when written to an image file I'm trying to get the colors from the list of materials that contain an emission node and write them to an image file, pixel by pixel. Everything seemed to be working but the pixel colors that get written are much darker than the colors I'm getting from the default_value field in my emission nodes. For instance, after running the following script, the first brownish red color (#160100) ends up as (#020000) in the .png file.
import bpy

size = 16, 16
image = bpy.data.images.new("palette", width=size[0], height=size[1])

carray = []
cindex = 0

obj = bpy.context.active_object
for m in obj.material_slots:
    if m.name:
        #print(str(m.material.diffuse_color[:]))
        #carray.append(m.material.diffuse_color)
        if m.material.use_nodes:
            for n in m.material.node_tree.nodes:
                if n.type=='EMISSION':
                    color = n.inputs[0].default_value
                    carray.append(color)
        #else:
            #carray.append(m.material.diffuse_color)

print(carray)

pixels = [None] * size[0] * size[1]
for y in range(size[1]):
    for x in range(size[0]):
        if cindex < len(carray):
            color = carray[cindex]
        else :
            color = [1.0,1.0,1.0,1.0]

        print(cindex)
        print(color)
        pixels[(abs(y-15) * size[0]) + x] = color#[r, g, b, a]
        cindex=cindex+1

# flatten list
pixels = [chan for px in pixels for chan in px]

# assign pixels
image.pixels = pixels

# write image
image.filepath_raw = "/temp/palette.png"
image.file_format = 'PNG'
image.save()

Credit to: @MarkyMarg2 https://twitter.com/MarkyMarg2/status/1290834859875692547 for solving this.
The colors need to be gamma corrected.
Each channel of RGB needs to be run through this formula:
if c < 0.0031308:
    srgb = 0.0 if c < 0.0 else c * 12.92
else:
    srgb = 1.055 * math.pow(c, 1.0 / 2.4) - 0.055

Here's a working example:
import bpy

size = 16, 16
image = bpy.data.images.new("palette", width=size[0], height=size[1])

carray = []
cindex = 0

def to_srgb(c):
    if c < 0.0031308:
        srgb = 0.0 if c < 0.0 else c * 12.92
    else:
        srgb = 1.055 * pow(c, 1.0 / 2.4) - 0.055

    return srgb

obj = bpy.context.active_object
for m in obj.material_slots:
    if m.name:
        #print(str(m.material.diffuse_color[:]))
        #carray.append(m.material.diffuse_color)
        if m.material.use_nodes:
            for n in m.material.node_tree.nodes:
                if n.type=='EMISSION':
                    color = n.inputs[0].default_value
                    carray.append(color)
        #else:
            #carray.append(m.material.diffuse_color)

print(carray)

pixels = [None] * size[0] * size[1]
for y in range(size[1]):
    for x in range(size[0]):
        if cindex < len(carray):
            c = carray[cindex]
            color_fixed = [1.0,1.0,1.0,1.0]
            color_fixed[0] = to_srgb(c[0])
            color_fixed[1] = to_srgb(c[1])
            color_fixed[2] = to_srgb(c[2])
            color = color_fixed
        else :
            color = [1.0,1.0,1.0,1.0]

        print(cindex)
        print(color)
        pixels[(abs(y-15) * size[0]) + x] = color#[r, g, b, a]
        cindex=cindex+1

# flatten list
pixels = [chan for px in pixels for chan in px]

# assign pixels
image.pixels = pixels

# write image
image.filepath_raw = "/temp/palette.png"
image.file_format = 'PNG'
image.save()


How do I append an object so it is still correctly connected to its armature? What are the tips for appending so that it works well? I tried to append but when the object comes in to the scene it's fractured e.g. bones don't fit the object, there seems to be multiple meshes etc.

Should I append in some specific order so that things come in the right place? First object, then bones, then material, etc.? I have the relative path set to ON if that helps.

The object is 'Sintel' from blender swap.

I foundt out that using the group appending was the key to this problem .


Fading Text In and Out - Video Sequence Editor I'm having difficulty getting text in my video to fade in and out. Currently, if I add text, it simply pops up without any transition.

I've attempted doing something similar to fading video clips in and out by using color and gamma crossing, but that doesn't seem to be doing the trick.

Could anyone help me understand what I need to do in order to get this to work? I noticed there's an option to mess with text opacity, but it doesn't allow me to make the opacity rise and fall throughout the timeline.

Thanks in advance for any help.

Get the latest beta version of Blender https://builder.blender.org/download/ - it will have fades in the Add menu:


preview image sequence composite I'm compositing an image sequence in blender, and would like to preview it while working.
image editor shows only a still image, and I don't want to export every time I wish to preview.
Is it possible to preview an image sequence while working (like after effect's ram preview?)

In the VSE preview window that the cube appears in press N for Properties and deselect the OpenGL Render. You should see the compositor output. If not, go back to the VSE window and press the Refresh Sequencer Button.


Strip Blender Down for just modeling Please keep in mind I am not trying to offend anyone!!! I realize that Blender is a powerful and a wonderfully free tool for people wanting to learn every inch of being a 3d artist and animator. However is there a way strip away stuff I am never going to use? It is just so cluttered I really only need a way to make 3 model's, Maybe a way to texture the models but even so I hear there are better tools for doing that? The Unreal Engine which is the game engine I am working with at current so I don't need the blender one. I have no interest in making short films or using the other tools in the package.

Blender allows you to save your preferred setup as a default, just turn off what you don't want to see and go to File > Save Startup File


Why does operators bl_idname have to contain 1 dot? Since anything before and after the dot is arbitrary, why bother?

Related error:

RuntimeError: Error: Registering operator class: 'abcdefg', invalid bl_idname 'abcdefg', must contain 1 '.' character

This rule may seem arbitrary, but looks like there's already some structure in existing operator's names. All registered operators will end up within bpy.ops module, and we can see that identifiers directly under it is reserved for modules/namespaces further categorizing the operators:

bpy.ops.action for animation data,
bpy.ops.object for object, regardless of data type,
bpy.ops.ui for user interface,
etc.

When we need an operator to quit Blender, it's available, grouped with other window management operators.

At first I, too, didn't bother with naming, putting everything under bpy.ops.object. But namespace distinction really helps to document, browse and search all the operators. Predictable identifier + Python console's Autocomplete feature made it easier to discover and build upon existing operators, including those from other addons.

I don't know if it has any other significance, but self-documentation alone made the naming rule worthwhile to enforce.


armature not getting attached to mesh Created an armature for a bird using animals meta-rig (I have downloaded a .blend file of a bird and trying to rig it)
I have adjusted all the bones to their places.
Using object mode, I generated a rig (but that rig was way too small, so I have scaled it)
Now I selected the bird Mesh and Shift selected the armature
When I am pressing CTRL+P I am not getting the option of deform (Originally, I thought this is happening due to behavioral changes in different versions, but more the videos i see, the more i am inclined to think this is the tipping point for my issue)
So as a workaround, I went to the Object option -> Parent -> Deform -> selected 'With automatic weights' (nothing noticeable seems to have happening here)
Then selecting the armature going to pose mode(ctrl+Tab)
When I am moving the armature, the bird is not moving.
Options I tried so far,

I tried joining with ctrl+J
Enabled the System Console to check the error (no error displayed)
My blender version : 2.82 (also tried with 2.83 version too)
Also ensured that "Auto run Python scripts" is turned ON in settings
Followed the instructions from this answer

I am fairly new to the world of Blender, and most of my knowledge is either through youtube videos or blender docs.
Attaching the file

This is the procedure to have your file working OK: select the rig and delete it. Select the Metarig and press Ctrl A "Apply all transform".
In the Rigify properties enable "advanced options", delete target rig and target UI and choose new (with a new name) as destination.
Press Generate rig.
Hide the Metarig.
Select the mesh, shift select the new rig (the order of selection is important), choose "with automatic weights" option.
The advanced option is necessary only if you generate a bad rig (wrong unapplied scale) and later you try to generate a new one: some conflict can arise between old rig (even if deleted) and new one.


How to make texture not repeat I've imported a face and shirt texture for a model but the shirt texture is repeating and overlapping the face texture where it is not specified to exist which creates this monstrosity.
I've got both materials in the editor

and the image is set to clip but it's still overlapping

You're a literal legend if you help me by the way.
Edit: This might not be a problem with repeating and more a problem with the wrong vertex groups being assigned to the shirt texture, there's a model with the correct textures in the blend file if it helps.
Here's the blend file link

There were multiple problems with the mesh, but it all came down to materials being assigned to the wrong places. The shirt material was assigned to the head, mouth, and eyes. Create new material slots for these areas, select the already working-on-other-character materials from the list of options for each slot rather than creating new ones, and assign them to the right places. Since several duplicate vertices exist, I personally recommend selecting all and merging by distance first, then using Select Linked but limited to UV to easily select one-material areas.
For more information, see the Blender Manual on Material Assignment


Hide Floor overlay from viewport render in Blender 2.8 In 2.79 Floor grid hides automatically when doing viewport renders, but stayed in place for solid view.

How can I obtain such behaviour in 2.8? Manual unchecking Floor from Overlays is a bit annoying

It's not automatic but I've spent a good amount of time searching for this myself and found out that you can toggle on/off all overlays (grid, outlines, etc) by clicking the overlay icon.

I know this is pretty late but I figured I'd post this in case. It's still annoying but it's better than having to uncheck/check each overlay.


Why drivering value from node editor is not working? I'm trying to get value copied from one cycle material node to another.
Why it is not working? (in my opinion it should work)?

I'm coping Data Path from one "Value" node:

and pasting it into single value driver:

But its not working. . .

Why?

Here's the full video of the set up:
https://youtu.be/8kmS5WF3JOM

Here's the file with my set up:
https://www.pastefile.com/BOyziq

Also find this confusing, but this thing is a bit tricky.

Important information

I don't know why, but RNA path for nodes isn't full when copying. For me, it is not working without adding node_tree. before copied data path.

Easy way

Add another variable, which defines object data (Loc/Rot/Scale). You don't need to add variable to expression, just make sure it is in the list. And better use neutral object or Empty to avoid cycle dependecy

More complicated way

Delete current driver and add it via Outliner. In Outliner switch menu to Data Block and find object that is using this material, then hit plus sign to expand tree and find material slots -> desired material -> material nodetree -> finally node you want to drive.

In other words, you should go through the whole data tree - from object to desired node's value.

Once you find line with value (for this specific case - Default Value), select it and click Edit in the header -> Add Driver

This is very brief explanation. For more info on Outliner method, watch this tutorial vid (from 19 minute).


3D manipulator stuck on left side of split viewport I'm using Blender 2.8. I split my viewport but accidentally moved the 3D manipulator to the right side- I don't know how I moved it nor how to move it back to the left side. The ride side is in rendered view. When I try to use the measure tool,  manipulator and other tools on the left side, I get an alert that says 'gizmo hidden in this view'.

It appears that you've hidden the gizmos in the left viewport, which is why the Move gizmo is invisible and the Measure tool gives you an error message. Enable them by clicking the Show Gizmos icon shown below.

Ensure that the following options are enabled in Viewport Gizmos.

The exact error message is "Gizmos hidden in this view" which is printed by view3d_ruler_add_invoke() (view3d_gizmo_ruler.c) when the Measure tool is used and v3d->gizmo_flag has the V3D_GIZMO_HIDE or V3D_GIZMO_HIDE_TOOL flags set. V3D_GIZMO_HIDE is set when Show Gizmos is disabled and V3D_GIZMO_HIDE_TOOL when Active Tools in the Viewport Gizmos options is deactivated.


Order of vertices added using Python script and bmesh I am using Blender 2.71 and Python 3.4.0 and I would like to add a row of vertices in such a way that I can call them using bmesh.verts[] in the same order that I placed them (or in reverse).

I have placed them using the for loop:

for x in range (0,5):
    bmesh.verts.new((x,0,0))

This results in five vertices in a row starting from the origin. However, the call order for bm.verts[] is totally muddled. For example, if I then run the following:

bmesh.verts.remove(bm.verts[0])

the one that disappears is the second from the right. I would expect it to be either the left or right-most vertex. Can anyone explain to me which method Blender uses to store these vertices?

The object contains no other vertices.

I have noticed that when adding four or less the order is sequential from right to left, but something changes at five. Is this something to do with polygons?

Thanks

Short answer is no, however...

BMesh only ensure vertices are added in-order when they are added to a newly created (or converted) mesh (which is OK for importers and geometry generators).
Once vertices are removed you cant rely on this.

Best use a list of your own to keep a reference to vertices added if you need this.

Sorting

if your really need to ensure some order, you can sort verts using the same method used with Python lists eg:

bm.verts.sort(key=lambda v: v.co.x)

However it would be inefficient to sort vertices every time you add once.


split face along edge I currently have two faces, overlapping at this point:

The option to split/subdivide the faces along this edge I made would be enough:

resulting faces should look like this:

Any help would be appreciated.

This method uses only built in functionality and does keep your UV coordinates in place.

First move the two inner edges so you will get a distinct intersections. Then select one of the intersecting faces and use the "Intersect (Knife)" tool (in the face menu). This will create an edge at the intersection between the two faces. It will also create some extra vertices that you need to dissolve.

Remove the overhanging triangle faces and delete them. Move the inner edges back to their position. Select the corner vertices and Remove Doubles.


How to determine visible faces? Is it possible to find the coordinates of the visible part of an object?

Background

I imported an object to a blender scene from Object File Format (OFF) using this blender addon (e.g. a chair). To segment the object in different parts I just removed some of the OFF face entries, which do not belong to the desired object part. Than I reimport the modified OFF.

Now I'd like to determine the coordinates (bounding box) of the object part, so only the visible and actually rendered faces (e.g. the back of the chair).

bpy.data.objects['object_id'].bound_box only gives the coordinates of the complete object (chair + back of the chair). Is there any way to figure out the part-bounding-box?

Example Scene:

I found a working solution. I just removed the vertices from OFF which did not correspond with any face. That leads to correct bounding box dimensions. To find the correct bounding box position of the part I used the following:

# create a cube for the bounding box
bpy.ops.mesh.primitive_cube_add()
bound_box = bpy.context.active_object

# copy transforms
ob = bpy.data.objects['off_object_name']
bound_box.dimensions = ob.dimensions
bound_box.rotation_euler = ob.rotation_euler

# calculate part center
centre = sum((Vector(b) for b in ob.bound_box), Vector())
centre /= 8

# set location using world matrix transformation
bound_box.location = (centre[0], centre[1], centre[2])
bound_box.location = ob.matrix_world * bound_box.location


how to apply texture paint I drawn his eyes and mouth in texture paint and saved the image as png file

However when I go to layout, my drawing disappears.
How do I apply texture paint to my character?

You first need to create the UVs. You need to unwrap your uvs. Enter edit mode. Select  the base of the neck in a loop at the base using edges. press CTRL+E >Edge Data>Mark Seam. Unselect all. Now make an edge selection starting from the base of the neck (in the middle of the loop you just selcted but starting at the middle of the neck, and select edges all the way up to the top of the head) CTRL+E>Mark edges.
Now: Select all: CTRL+U (unwrap) while still on EDIT mode. Then you have a UV map. Finally apply the texture you created. You´ll get distorted things. Start painting again, only this time you will see your UVs and your Material and Your textures.

Thank you for your consideration to vote me as the answer by clicking to the left :the icon with a check mark and upvote this answer.

BFCT_Schiller


Displace modifier RGB to XYZ Direction, how to invert on the x axis only I have two high poly objects, both with a displace mod and their coordinates set to global, their  direction set to 'RGB to XYZ', the strength set to 1 and the midlevel set to 0 but they both use a slightly different texture map that's actually a movie. my goal here is to get some really jagged points based on the texture from some of the geometry and point them all towards a specific vector from where they're grabbed from. the thing is my first one is angled exactly how I want but the other one cant seem to 'mirror the first ones angle. what I thought I should do is go into the Material settings > Colors > Clamp and disable it and then make the Colors > RGB values negative numbers but this doesn't seem to work despite the tool tip in the Clamp bool implying as much. I've tried several things, including trying to use some nodes which I know nothing about and never even got close, and I'm still not sure how to reach my goal. My main questions are:

Dose the clamp work like I'm using it?

Is there a way to combine two displace mods that doesn't stretch the points along two axis being used for each direction?

Can I get any advice on how I could achieve my goal?

All help is greatly appreciated and ill give more info as its needed.

I have solved my issue using nodes rather than a modifier thanks to the suggestion @Allen Simpson commented. I'm fairly new to the workflow and application of shader nodes but I will try to explain in more detail.
My issue was that I needed to turn my texture map into a Vector Displacement node to point my displaced geometry in a consistent direction something the Displace Modifier can also do using the textures RGB values. the only issue is the modifier method requires you to set RGB values in the Texture Properties > Colors > R,G,B and it only accepts values 0-2. you can use the strength value in the Displace Modifier to multiply that value even in the negative direction but it applies it to all 3 RGB values equally. not sure if there is a way to do what what I needed via the modifier but that's ok.
After giving the shader nodes another go I found the Separate RGB node and everything clicked from there. After feeding it my color from my Image Texture nodes output I fed the R value, which represents the only axis I wanted to modify, into a Math node and multiplied by -1 and fed the output and the G and B into their respective X, Y, Z values in a Combine XYZ node. Then I dropped that output into a Vector Displacement node to give the displacement its direction.

With this solution you can easily build a vector by adding a Math node to each of the other values on the Separate RGB node before combining them as XYZ!
Also to answer my own other questions;

Clamp works like Clamp in the Mirror Modifier in that IF there are any values below 0 and Clamp is turned on, it reverts to 0 but it does not automatically grant your colors RGB values to go below 0. No such thing as a negative color value after all. Not sure if there is a way to get the negative values for the Displace modifier but its not that way. Nodes do a good job of letting you take a value from the color and then mod it as you need. Much easier imo.

Not sure but it seems like a harder way to do this, but it would be good for getting a different effect. I think it can make really psychedelic kaleidoscope like geometry animations?


Is it possible to convert a procedural texture into actual geometry? As we now have volumetrics in cycles, it's possible to render procedural textures in 3D.

For example, you can render a cube:

Like this:

However, is it possible to generate an actual mesh based on the intensity of a procedural texture?

I tried to do something like this:

Simulate particle system being affected by procedural texture
Convert particle system to vertices
Mesh using the convex hull modifier

But I failed because:

I couldn't get the particles to group convincingly based on the intensity of a texture
The result was concave, so the convex hull operator was not useful.

How can I generate a mesh in this way?

Particle is a nice idea to do this, and it is possible to control the volumetric density by procedual texture:

Demo file

Edit:

As MarcClinton mentioned in comment, a nice addon called MSMesher can be a relatively nice solution:

The result looks similar to metaballs, which means, to generate a sharper shape, further remeshing would be considered.


How to get emitter particles to stay static? I'm trying to animate my first blender render (https://www.instagram.com/p/B6zkzSTDqiC/) and having trouble gettings the particles to stay put. The bushes next to the entrances of the building are created by particles (from a sphere object) and when I start the animation, they automatically fall down because of the gravity of the scene. So a question here: is there a way to have the bush particles stay on the sphere when I start the animation?

Thanks!

Probably you won't need all of these, but to stay on the safe side:

the Start and End time of the particle Emission must be 1 (all particles emitted at the first frame) and their Lifetime must be 250 (or the animation length in frames)
the Velocity must be 0 in each one of its components. Including  Normal, that is 1 by default!
Physics Type should be set to None
the Field Weights called Gravity and All must be 0 (this is redundant, since Physics: None should guarantee this already)

To summarize:

(Hair particles, on the other hand, won't move by default. Unless Hair Dynamics is selected; in which case, deselect it.)


Round the end of shape (mesh) I have created a bezier curve, applied a bevel and then converted it to a mesh. Is there a way to round the end of the shape? I have tried the bevel modifier but it didn't work as i hoped.
It is like this:

I want it to end like this:

Thanks

The bevel of a curve can be given a Taper Object in its 'Data' tab > 'Geometry' panel:

The radius of the bevelled curve is varied according to the Y of the taper curve in the taper-curve's  own object-space.
As shown, the bevel can be mapped to less than the full extent of the curve, and there are various settings for the interpolation of the mapping from point to
point.
But, adjusting the number of subdivisions in the bevelled curve to capture, not only the curvature along its length, but also the variation in its radius, can be a bit fiddly.


Cloth Pinning checkbox missing in Blender 2.8 There is no option to pin a vertex group to hold the cloth at the position!

2.79 had this feature

Oh I missed that!
It is under Shape Menu.


Ik Stretch: Finding the Proportional Value I have a tedious problem with IK stretch, and haven't found any hint when googling it.
In a 2 bones IK chain with stretch, how to find the exact stretch value for each bone so that they are scaled with the same factor?

Let's say we want to stretch these two bones, same length in rest position. The third one at the top is the target.
Setting the stretch value to 0.5 for each gives a correct scale of x2 when moving up the target bone to multiply the chain length by 2 (picture 1 and 2, click on the pic to expand it and see the unit grid better)

But, when dividing the first bone length by two in edit mode, the stretch is no more proportional (picture 3).
The first bone should reach the red line to double its length, whereas it's a little higher.
It's still possible to manually lower and find by iterations the stretch value of this bone to get the right scale, but i'd like to find the exact formula to write it in a python script.

Blend File

Thanks for any help!

Finally found the answer from Rigify scripts:

    l1 = ulimb_p.length
    l2 = flimb_p.length
    if l1 < l2:
        ulimb_p.ik_stretch = (l1 ** (1 / 3)) / (l2 ** (1 / 3))
        flimb_p.ik_stretch = 1.0
    else:
        ulimb_p.ik_stretch = 1.0
        flimb_p.ik_stretch = (l2 ** (1 / 3)) / (l1 ** (1 / 3))


How would you model 'a sphere with a shell' like object? I am trying to model this thing, but the silver cover on top is what I have no idea how to go about.

And the blue-ish reflection I believe is from the sphere being cast on the inner side of the silver bits.

Any help would be much appreciated.

Just create your sphere and over it draw the shape of your cuts using a Bezier Curve object.

Adjust its shape as necessary, then use knife project to cut the shape.

In object mode select your curve, then without deselecting, select your sphere, by this specific order. Enter edit mode on the sphere and with all faces selected use Knife Project with the option Cut Through active.

Carefully select all the unwanted parts then remove them by deleting the faces.


Modeling How to solidify or scale an irregular shape, maybe flip vertices? I'm trying to make an irregular shaped wall and the inside will be a flower bed.  I started with tracing shape as bezier then convert to mesh but it all got messy.
this time i started with plane, deleted all but one vertex then extruded and used proportional editing to get the shape.
however, i now need to solidify the shape so it's one brick thick and then i will extrude in z axis.
Solidify just went weird and twisted, i managed to flip the normals in z direction but that didn't help solidify as it was in the wrong orientation.
I tried to duplicate and scale hoping that all vertices would move out the same amount...but that didn't work. i'm thinking that it must be to do with normals, which you can see her point in weird directions (and also slightly elevated in z-direction)
ANy help would be great. Thanks
UPDATE: Gorgious method worked for the solidifying. thanks.
however, i'm still intrigued as to how you could have scaled the original shape to make a "larger" version of it. whenever i scaled it, it would scale disproportionately and in weird directions

You have converted it to a mesh, and then extruded the points in edit mode.
Another way you could try is to keep it as a bezier curve and remain in object mode and go to
object data properties>geometry>extrude
You can set the bevel and offset at that point, and then convert it to mesh afterwards.
This seems to result in very smooth geometry.


The character arm rotates the wrong way after 180 degrees Currently, I am try to make a character rotate their arm by around 240 degrees. However, the rig decides to to take the shorter 120 degree way. Why does this happen and how can I fix this?

The answer turned out to be simple. For the arm to rotate the correct way, it simply had to have all of the bone rotation values inverted.

The values were previously,
W: 0.262,
X: -0.720,
Y: -0.604,
Z: 0.220,
but were inverted.


Newbie from 3DS Max. Ignore Backfacing ? Limit Selection to Visible ? 2.80? Veteran user of 3DS Max, I'm one day into learning Blender 2.80 but am struggling with selecting ALL faces of an object including those which are backfacing.

My searching has mentioned that there is a Limit Selction to Visible which needs to be unchecked but where is that in Blender 2.80 ?

Many thanks.

I guess what you're looking for is this option, Show whole scene transparent, altZ to activate in whatever shading mode you are:


Arrange order of items in collection / outliner? I’d like to manually rearrange my items within a collection but dragging doesn’t do anything ? I’ve turned off Sort Alphabetically but still no joy. Maybe this isn’t possible yet in Blender 2.9 ? I like to keep things organised like in C4D. Any help would be much appreciated.

Even though you can't manually rearrange objects like in C4D, you can use an "Empty" which is the equivalent to a "Null Object" to separate objects inside a collection.


Blender Game Engine - How i can make my turrets aim the enemy that’s closest to the village? i am trying to make a TD game.
I need to make my turrets aim the enemy that’s closest to the village and i’m stuck.
My turrets aim the last enemy that enters their firing zone instead of the enemy that’s closest to the village and are in their firing zone.

Any help?

I believe that your question has already been posted and answered on blenderartists here

.blend file here

======================================================================

Additional info:

Q:

  what’s the difference module vs script in the logic bricks??

A:

  script is for 1 object to use, module can be used by multiple objects, so instead of 1 tower you could connect 100 to it.

#Logick Bricks : (Always -> Python-Module track_to_closest.track -> Edit object - Track_to)
# and a property "track_distance" on the object using this script
# and place a property on the objects you want to track to: called track_to

def track(cont):

    own         = cont.owner
    scene       = own.scene
    track_to    = cont.actuators['track_to']

    ai = [obj for obj in scene.objects if 'track_to' in obj]

    if ai:

        closest_ai      = sorted(ai, key=lambda enemy: own.getDistanceTo(enemy))[0]
        distance        = own.getDistanceTo(closest_ai)
        max_distance    = own['track_distance']

        if distance <= max_distance:

            track_to.object = closest_ai
            cont.activate(track_to)

        else:
            cont.deactivate(track_to)


Is Blender suitable for this project? Can the community help to know if Blender is suitable for my project. I'm looking to create a 3d shape of xyz vector components that oscillate in size out of phase. The phase shift between vectors to initially be 120degrees but with the potential for varying. The ultimate goal is to get a probability distribution vector for each axis.

I think Blender is perfect for your project, you can do all the math with Python, and if you don't know the language it's very easy to learn, even if you don't have programming experience before because it doesn't have a complex syntaxis.

If you don't want to use code for it or it isn't as complicated then I think Blender is still the best choice because you can easily transform an object an exact number of degrees and come back to change that number as many times as you want, and the graph window for the animation curves has also great tools. Also, if you need some measurements that you can't get with vanilla Blender, I bet you can easily find an addon that does that.

Also, it's free and has extensive documentation.


Fractal Noise in Blender Stretches From Origin Point- Why? To make a good noise for terrain generation you can hook up a noise texture to the scale of another noise texture. I like using this, but I noted one limitation- if the texture coordinates become displaced too far it does keep a constant pattern. You can visualize this well by viewing the volume of the output- the noise seems to stretch out directly away from the origin point of the object the farther away it goes. Why? How can I prevent this?

Procedural textures should generally never have variable scale - since the scale affects the "size" of the pattern in relation to the origin, varying the scale close to the origin will have small effects while this is magnified the further the point is from the origin (as all that space between the origin and the point has been scaled by the same amount).

A better solution is to distort the texture coordinates to 'compress' or 'expand' different regions of the texture based on the noise, rather than adjusting the scale. This will have an effect that is consistent regardless of distance to the origin.

For example, consider the following nodes :

Here's instead of the Noise varying the scale, the noise is combined with the coordinates to shift them a varying amount. This varies the rate of change of the vector as it moves across the texture, compressing some regions and expanding others. This can produce the following result :

Varying the properties of the Noise affects the frequency of the distortion and the Value node used for the multiply will affect the strength.


In which direction should bone axes be oriented? A total noob here I'm afraid. I've followed a couple tutorials in order to create a human mesh and set up an armature, however I've hit a roadblock with bone-rolling.

How should I orient the bones' axes so that I can successfully paste an x-flipped pose? I think I got the legs and spine working, but I have no idea which way the axes should be for the arms. I've messed around with the Ctrl+N bone-rolling option to align the bones in various directions, but I'm not sure what end result I should be looking for and none of what I've tried seems to work.

Here's an upload of the file: http://www.fast-files.com/getfile.aspx?file=78626

UPDATE: Problem fixed! Thank you for your helpful responses. Turns out I had a key issue of the opposite arm IK bone I was testing being named slightly wrong. facepalm But once I was clear on how the axes should be oriented and confident I had it right it was a lot easier to see what the real problem was. Many thanks!!

In Blender the Bone's local Y-axis always runs along the bone's longitudinal axis (from head to tail). I believe this convention comes from the definition of the bvh format.

Regarding the orientation of the local x and z axes a typical approach seems to be to to orient all bone's local x axes along the global x axis. However this does only work for bones which have their local Y axis oriented mostly along the global Z-axis.

So this general rule does no longer work when you have a character that is in T-Pose for example. In that case i found that a common approach is to orient the local z axis along the global z axis.

I have made my own convenience rule of thumb out of this:

for mostly vertical bones: orient their local x axis towards the global x axis

for mostly horizontal bones: orient their local z axis towards their global z axis

These rules of thumb worked for me in most cases so far. The only wonky situations are where a bone is half vertical half horizontal. I think i then used the same orientation as the other bones of the limb have.


Merge 2D irregular shapes to generate 3D solid I have 2 SVG shapes. Consider them as top and bottom faces of an object. I want to 'blend' one shape to the other to create a 3D solid. They have a differing number of vertices. Am I able to do this in Blender? I have limited understanding of Blender, but from viewing various YouTube videos it strikes me that what I am attempting should be relatively straight forward?

If anyone can point me to a tutorial I'm happy to give it a go.

Thanks, Darren.

Tried the suggestion below and got this:
Are the shapes too complex (hard to believe), note number of vertices? I get the feeling there should be some control vertices that would avoid the cross-over effect?

Join both objects together (Ctrl+J) if not joined.
In Edit mode select outer edges of upper and lower parts, hit Ctrl+E and select Bridge Edge Loop


How can i make a blade out of plane like in the tutorial? In the screenshot on the right it's how the blade should look like from the tutorial video. On the left is what i have down so far.

When i select the left bottom corner vertice and then on the left menu click on Translate when i change the x or z i'm not getting nothing even close to this.
In my model it's like extrude it.

This is the tutorial: Tutorial

And he make the blade on minute 22:24

It looks like you should use the bevel tool. Switch to edge selection mode and select the edge you want to add a smooth edge too. Then click cntrl+B, you can change the size by moving your mouse up and down, you can also make it smoother with the scroll wheel.

Is this what you want?


unwanted Purple colour in my render so , i started making a short film of a robot mystery , and had made a few renders , it was all okay , until i made my 5th render , the whole lighting system glitched and the lights started pitching to purple , first i thought , that my hdri might have caused the problem but the hdri is attached but still , this is the problem
PS , im a noob

Perhaps you changed where that HDRI file was, reloading it may solve the problem, either that or you disconected a node somewhere.


Parts of the mesh don't move when moving bones I just started using Blender, so I don't have much knowledge about its tool and stuff. Anyway, I was trying to animate an object, put the bones and assigned the vertex that wanted, etc. But when I move a bone that moves other bones together, some parts of my mesh stays behind. I checked to see if I have selected some wrong vertex, but nope. I believe it has something to do with loose faces that has no edge and vertex, but I'm not sure and have no idea of how to fix it. If anybody could help, please! I'm desperate! And thanks!

The vertex of those parts that stay behind means you don't have them assigned to any bones to move them. Check all the vertex groups in weight painting mode and most likely they will be blue for all vertex groups.

You can select a vertex group while the mouse pointer is still in the list you can use the up/down arrow key to select all the vertex in the list to check quicker.

Then you need to weight paint them with the Add brush to the desired vertex group.


Straightening tilted viewport I am not sure how I got that tilt. How can I get the viewport to be correctly aligned again?

If it's the viewport camera, simply hit NUMPAD1, NUMPAD3 or NUMPAD7 to get into an aligend view. Alternatively use the View menu (Right, Front or Top).

If your camera object got tilted, open the properties with N, find the rotation values in the Transform panel and find the value that isn't quite 90 or 0 degrees and enter a clean value.


Render shadow lines problem Hi there well I'm kind of newish to Blender and my problem is when I do the Rendering I get some ,,shadow lines'' you can see them if you zoom in at the head, how can I avoid them or what did I do wrong in the settings.

Thanks for the help :P

Thx to Serge L I could figure out with different tries of the denoiser size and the amount of samples to get rid of the artifacts, the shadow/color lines could have been caused of the to dark scene so they mostly disappeared with more or brighter light, now Im happy with the result and can go on thx for the help guys.


Vertex painting smoothly anyone know if there's a way to avoid this while vertex painting?

Thanks

The easiest way to do this would be too increase our blead value in the options panel of painting. The only problem with that is you might have to move your uvs around a bit so they won't bleed into each other.


Transfer settings to new version of Blender I use Mac OSX 10.9.5. A year ago, I downloaded 2.75a, and today, I downloaded version 2.77a. I downloaded both via .zip file from blender.org and dragged each into the Applications folder of my Mac.

In 2.75a, I had done some painstaking remapping to accommodate my Magic Mouse and Apple Wireless Keyboard, in addition to a pretty shiny custom theme. I didn't want to redo these settings.

How could I transfer my old settings into the new version? Apparently due to my method of download, "Copy Previous Settings" did not show on the splash screen. I searched "Copy Previous Settings" in the new version via the spacebar, and it returned an error: "Users/aubrie/Library/Application Support/Blender/2.76 does not exist". From this, I figured how to copy my old preferences.

You can always use the new Blender Cloud Sync addon. It requires a Blender ID (free) and the addon (free). It allows you to upload your preferences to the cloud, and download them anywhere in Blender.

(Image from cloud.blender.org)


Live rendering problem in all viewport modes other than Rendered I have suddenly had a problem with how the kitchen I'm designing shows up in the viewport, using Blender 2.82. I tried lots of searching for a solution, but I must be asking the question wrong: except when using cycles to render or in wireframe mode, the scene is jagged and full of holes. Moving around the viewport makes lots of flashing and stuttering unless it is in wireframe mode. It was not this way before, it just suddenly happened and restarting didn't fix. I am new to blender, so I'm I'm sure I just clicked something accidentally. Any help would be greatly appreciated...  Here's some screen shots:

original

now:

cycles render

It looks like your clipping distance is not set optimally for this scene.

Generally when I see this issue, the Clip Start is set too low, and the Clip End is set too high. Try increasing the Clip Start to around .1m and the clip end to 500m

Note: These numbers assume that the Blender file is using real life measurements, or reasonably close to it.


Most mouse and keyboard inputs stopped working in Blender 2.80. How can this be fixed? I have had this issue previously and I have it again. Most inputs in Blender stopped working. I can't select objects or click most buttons and keyboard shortcuts aren't working either, neither does touch or pen on the tablet. I downloaded the newest release candidate and the issue is still there. I reset settings to factory settings and the issue still persists. What do i do?
I have tried turning the computer off and on again.

Windows 10, 64 bit Blender 2.8 RC3

Solved it. Resetting to factory settings didn't help, deleting the 2.8 folder from appdata did.

If you have a rig in the scene, make sure you aren't in "pose" mode. If in pose mode you can't select the mesh just by clicking on it. You must switch to object mode first.


How to make all keyframe scene visible objects, visible in the renderer for each keyframe I need urgent help on this for a project that's due. I didn't know there was a camera renderer that also need to be altered i thought it was scene view the whole time. (there's probably a script that does the job,but i can't find it), so all my objects that weren't meant to be visible all show at the start and i could go to that small camera icon each time and set the visibility keyframe manually but it would take way too long.
I have camera, texts from blender, plane from blender, plane with images and a armature installed from https://www.blendswap.com/blends/view/76197

Here are all the objects in the dopesheet. At the moment all i could think of to solve this problem would be scripting,but the documentation is bad, so i need expertise.

Someone could have mentioned a quick fix... the openGL renderer uses the scene view and i spent the whole of last night trying to figure out ways until today. Thanks a lot guys.


Pack rendered images into .blend? I have a problem: I render images, and if Blender accidentally quits while performing some sort of operation, I lose my rendered data. (If only a single unsaved image).

I have external data > 'Pack all into .blend' enabled, but this does not pack rendered images into the file.

Is there a way to pack single rendered images into the .blend along with all of my already packed textures?

This would be extremely helpful, and would save a lot of render time!

If I am correct, you want to automatically save the rendered result so if Blender crashes you have the last known output.  Using composition you can save the output as follows:

This image, by default, will be called Image0001.png in your chosen path. If you really really really wanted to pack it in the Blender file I suppose you could create a non-rendered object that takes that image and then it should also be stored (not tested). However, I think just the automatic saving is probably what you are after.


Problems with particle hair in 2.72 (cycles) So I made some hair in blender using cycles and as soon as i hit animate (the play button in the time line) it strongly resembles her standing in a pool of water with a live overhead powerline in it.

Obviously I am missing a setting here some place.

(video included.)

https://www.youtube.com/watch?v=L3fG4QBpNTE&feature=youtu.be

I struggled with the same problem. Here is my example:

In my case I set up the hair settings, and then realized that the mesh isn't perfect. Then I tried to remove doubles, and change the geometry.
Every time you change geometry (actions like: deleting, separating, ripping vertices) with the hair settings set up, you may see this problem appear.

My advice is to (before setting up the hair):

Apply rotation, location and scale. Ctrl A
Remove doubles.
Apply mirror modifier.
Recalculate normals. Ctrl N
Check the mesh using "mesh lint addon" and make sure the mesh is 'clear' (has no ngons and interior faces).

After applying all the things mentioned above my problem was solved.


Changinng in-game Armature Object's Armature Data I'm my current game project my main character needs to transform into another character, i can easily change the mesh data from the gameObject, but i can't find any documentation about changing the Armature data for my Armature object.

If you are talking about Armature datablock, it is similar as changing the mesh data for mesh object:

If you are talking about changing Action Data for armature, there are two places to go, depends on your actual need:

For BGE action, you may take the 2nd one.

PS: Action Data exchanging between armatures requires high similarity, in other words, same hierachy, same bone count, same bone names, etc. Otherwise it will not work as expected.


Imported PNG shows black instead of transparency in the background Importing a 'smoke' image as a plane shows no transparency.
Still have black background.

What other settings should I tweak?

The image you uploaded contains no alpha channel.

You can check the alpha channel for the image using the channel display switches at the bottom of the UV/Image editor window

Blender will not magically create an alpha channel for you, if the image contains none.

A half-ass solution (without getting into editing in an image editing app, or sourcing an image with a proper alpha channel), is to use the black and white representation of the image itself as a mask to control the mix between an emission and a transparent shader, so that the white pixels of the image will be emissive and the black ones transparent.


Reusing Animations for another character? Are you able to reuse an animation on a certain rig for one character to another identical rig corresponding to a different character/model? I want to know because I want to practice animating a lower value model until I am ready to work on my characters. Then, I want to reuse those animations on the characters' rigs.

Thanks!

Yes, but you have to make sure that the objects (rigs) are identical.

The Action Editor

Either open up a Dope Sheet window or change to the Animation Screen layout.

Change to the Action Editor in the dropdown menu where it likely currently says Dope Sheet.

 -->

If you select the rig that you already have animated, it will probably display something like ArmatureAction where it says + New in the above screenshot. If you select the unanimated armature, you can select ArmatureAction from the dropdown menu to the left of + New.

The Process:

This can work for any number and any type of object. For example, if I have a cube keyframed for X-Location and X-Rotation, I can use the same method to copy its movements to a nearby cone and cylinder.

Extended uses:

The demo .blend:

Hope this helps; feel free to ask questions!


Cycles render, noisy even when using a high number of samples I've seen other questions around, but none that answered my current problem.

I've been working on this scene for a few days, and when I wanted to render it, the produced result wasn't quite like I expected, very grainy:

Here's a detail:

This was rendered at 500 cycles.

A previous render when the scene wasn't finished gave much clearer results:

What could be causing this, and what are the basic things to check to troubleshoot this kind of problem?

EDIT:
Here's the .blend file (click on the orange button, sorry about the ad pop-up, the file is over the 30 mb limit of blend-exchange, feel free to suggest alternative hosts in the comments)

The issue here is that even though you set your scene to render at 500 samples, that number is being overridden and is controlled by the number of samples on the render layer.

And there you have set the number of samples to 6...

Any number other than zero here will become the total number of samples used for this particular render layer.

On the on the scene sampling section you will see a new control for "Layer Samples" the default is set to Use (meaning that it will use the number of samples set in the render layer section).

So instead of 500 you are just using 6 samples...

To fix this issue you have a two choices:

Set that Samples number to 0 in the Render layers, so that the control reverts to the scene settings.

OR

Set the layer samples to Ignore.

Then you'll get a nice clean render using all 500 samples.

Other tips:

To bring the noise down without a high number of samples you can also use branched path tracing

For cleaner images enable the Multiple Importance sampling for your lights, Emitter planes and environment.

For More info read this posts:

What is multiple importance sample option

When should MIS be used and when should it be disabled?

Now as a final note, not necessarily related to the noise: it seems to me that polygon density for your objects is too much: The total number of vertices for such a simple scene the is over one million vertices and faces... just the emitter object on top of the table has 4225 vertices, when it could easily have just 8 or even 4... In your subsurf modifiers you are using way too many unnecessary subdivision levels, bringing the polygon count way up for such simple objects. Most of the subsurf modifiers you have set at 6 for rendering...Do you really need that many? You certainly don't need subsurf on the flat floor or walls or for most of the flat table... Having that much unnecessary geometry will have a negative impact on the performance of your computer. To get an idea of how many more polygons you generate when you subsurf please read: https://blender.stackexchange.com/a/15667/1853


Mesh with weird inverted light direction Sometimes while editing meshes I get stuck with a weird kind of behaviour. I know mostly it happens due to my fault as a newby, but I need find the way to fix it.

Step by step explanation appreciated.

https://www.sendspace.com/file/7pyhz1

The obj file has bad normal data for some reason, which gets imported into Blender. The way to fix it is to delete any custom normal data using the 'Clear Custom Split Normal' button from the object data panel.


How to reapply symmetry in sculpting? I have been sculpting a human head using dynamic topology. I've been primarily sculpting on the right side of the picture below. At some point, the mirror got messed up and shows the eye on the left side incorrectly.

How do I reapply the mirror from the right side of the picture above to the left side?

If you are using Dyntopo, then just click the "Symmetrize" button under the Dyntopo settings panel. Just make sure that the "Direction" menu is set correctly. The default is "-X to +X". If the side that you want to keep is in the "-X" direction (away from the red arrow on the manipulator) then leave it how it is. If not, change it so that the first direction is the side you want to keep, and the second direction is the side that got messed up. This way, you don't have to leave your workflow and you can stay in Sculpt Mode.


Blender - b Why blender is quiting? ds@ds-OptiPlex-3040:~$  /home/ds/Documents/blender2.80/blender -b
Blender 2.80 (sub 74) (hash 38d4483c6a51 built 2019-07-18 17:31:04)
found bundled python: /home/ds/Documents/blender2.80/2.80/python

Blender quit

The -b command line option tells Blender to run from the command line. But it expects you to pass on a further sequence of commands. If you don't, Blender just quits because you gave it nothing to do.

Also note that the order of commands matters. blender -b -S Scene2 filename.blend -a for instance will open the default scene, then try to switch to Scene2 (which won't exist), then open filename.blend, and then render the frame range defined in the file. After that it quits. blender -b filename.blend -S Scene2 -a will on the other hand first open the file filename.blend, THEN switch to Scene2, then render the animation.

See the manual for more information on this matter:

https://docs.blender.org/manual/en/2.80/advanced/command_line/launch/index.html
https://docs.blender.org/manual/en/2.80/advanced/command_line/arguments.html


Inside of mesh is see through when trying to make a hole? I am trying to make a hole in this mesh:

but when I delete the vertices/faces, this happens:

How can I delete the top and bottom in the middle without this happening? I want the inside to look like how it does on the outside, not look like there is stuff missing.

What it looks like when rendered:

After finishing your model do the following:

press A to select the entire mesh
press W, select remove doubles
press CTRL + N to correctly orient the normal ones
press A to deselect everything
exit to object mode and export following the instructions

NOTE:

your blender is probably damaged, or some addon is causing you conflicts

I made the following example I exported it to unity, roblox and U4, and it worked well, it is possible to say that the risk of having a bad problem or having problems is greater because I use my own compilation and fork of blender to work, which I have modified in many parts, if you use a release version of blender.org you shouldn't have any major problems than the ones I could have


How to control complete model with single empty I have several empty's and i want to parent all the empty's to a new empty to control my model to rotate, scale & move. Some empty have rotation limit some have location limit. Some are just mesh without empty. I want to control my complete model so that i cant rotate scale and move. I tried to add a empty and selecting all the empty and mesh and last the new empty and parented. It do parented but working of the limit rotation and limit location not working. Any suggestion or help how it works. Thanks.
(video)

do you mean like this?
https://youtu.be/k_ks-DzSBV0
if yes:
Parenting the empty works exactly as you described.
But...
you have to change your limit rotation settings.
I just had a look at your fold constraint.
The correct setup looks like this:

You have to restrict all axis except the one you want to move (in your special case here) so just the x-Axis got some values, all others with 0 but checked.
I am not sure why it does not work if you check the lock on the axis values, but with my settings it works.


How to set start and end frame for hair animation I have an animation with an object that "grows" hair in the middle (animating the render->end->timing in the particle settings). It seems that the hair exists from the very beginning of the animation, and even during rendering of the frames before the hair appears, the "Building BVH" step in the render takes forever. Is there any way to make the render before the hair appears faster? Any help is appreciated. (I'm using cycles and blender 2.8, but I can probably convert an answer from 2.79 into 2.8)

Thank you to @FFeller for his comment, it really answers everything, but since he didn't write an actual answer, I will answer my own question for future viewers.

In order to disable a hair animation for part of a render to speed up BVH creation, as FFeller said in his comment, one would insert keyframes on either side of the period where the hair is present in pairs, with the enabled pair on the inside and the disabled pair on the outside (probably with one frame difference between enabled and disabled keyframes, otherwise results can be rather strange). This would be done by navigating to the correct frame, setting the camera icon to either enabled or disabled (depending on which is needed) and then pressing "I" over the icon to insert a keyframe. The icon should now be highlighted in yellow and there should be a keyframe on the corresponding frame.

keyframe which is set to enabled

keyframe which is set to disabled


How to preserve Cycles material colours when exporting to .obj format? When I export .obj files from scenes that use Cycles (and thus, materials with nodes etc), the material colours are not preserved in the .mtl file.

So, what can I do to avoid this?

As mentioned by Jebediah Kerman, the viewport color in Material > Settings is exported to the .mtl file:

If you only have a few simple materials, it can be quite trivial to copy the colors by using CtrlC and CtrlV while hovering over the color selection boxes.

If you have many materials, you could write a python script to take colors from the node tree and set the viewport color accordingly.

For example, here is a simple script that looks for diffuse shaders and sets the viewport color to the color of any diffuse shaders found:

import bpy

for mat in bpy.data.materials:
    if mat.use_nodes == True:
        tree = mat.node_tree
        for node in tree.nodes:
            if node.type == "BSDF_DIFFUSE":
                col = node.inputs["Color"].default_value
                mat.diffuse_color = (col[0],col[1],col[2])

Note that the Viewport color is actually diffuse_color.


GPU doesn't render the image with many moving particles I recently was making a scene with particles being moved from forcefields and after making the particles over 100k
But while rendering as always the first frame didn't show the particles at all but in second frame where the particles should've appeared GPU simply doesn't render, but CPU does it but in a detail lossy way. I tried on my PC (GTX1070) and at friends PC (RTX2070 super) both had absolute same issue.

The reason why it struggles so much is the motion blur. since it has to know where the particle was to make the blur effect. and with so many particles looks like GPU just cant keep up. simply turning off the Motion blur helped, but if you need motion blur, you probably need to use CPU Only render. Why CPU only? because if you use GPU render with CPU acceleration the tile that supposed to be rendered with GPU won't let the CPU finish the job.
I hope it will help someone :)


Blender twisting parts of mesh when rigging I have a problem when I rig a mesh and that is when I put the arms of my mesh up in the air for example some parts of it get twisted.

I've tried looking at the XYZ orientation and the weight painting with no succes.

Here are pictures illustrating the problem. (possibly NSFW, hover to view)

here is the .blend file

female base rigged

The problem in your scene is caused by the bone structure. Take the L side for example:

Since you are using two bones for each upperarm for some reason (which is unlike normal human), the constrained bone DEF-upper_arm.01.L doesn't follow the rotation of its control bone or even DEF-upper_arm.02.L, which would lead to the problem. As shown below:

There would be a few ways to fix this, but I'm really not sure why you structed and set the control bone for upper arm like this (I assume you are trying to simulate the natural-looking muscle stretch). However, I think at least an additional Copy Rotation constraint onDEF-upper_arm.01.L is needed here.

Here is my try, FYI: