This is a custom "WAN Start to End Frame" node that replaces the nodes_utility.py provided by kijai's "ComfyUI-WanVideoWrapper". That file to replace is usually found in your custom_nodes/ComfyUI-WanVideoWrapper folder.
What does this do?
It basically allows you to use a "start frame" AND a raw video motion (no controlnet processing required) at the same time. You'll still get better results with ControlNet for what VACE can handle, but this gives you another option for messing with non-ControlNet motion.
It adds two new parameters to the node: "control_strength" and "control_ease".
control_strength: When using a start frame and control_images (that will contain motion), how strong should the motion be applied to the WAN generation? Too much will change the video significantly to match your control_images. Too little will not bring enough motion over. Values around 0.1 to 0.5 seem to work best, maybe. Values of 1 will use default behavior.
control_ease: How many frames to "ease in" the control_images motion? Starting too quickly can cause a strange early jump to try and match the motion to your start image. This is to give more time for your start frame to line up with the control_images motion. If your starting frame is very close to the motion start, try low values (like 8). If you have a very different motion from your starting frame, go with 24 to 48.
Replacing this file could break your WanVideoWrapper with future WanVideoWrapper updates. It may be more compatible just replacing the 'class WanVideoVACEStartToEndFrame:' code with the class code from my file.
I should probably have a fork and offer a pull request for this, but for now, I'm just providing the file if you want to use it. If Kijai or anyone wants to bring this over if y'all find it useful, it is much appreciated.