World Motionvector Pass

Hey All,

Is there a common agreed best way to get an overall motion vector pass out of an unreal render, preferably one that is formatted (uv = r/g),
so it can be mixed with motion vectors coming from traditional 3D packages such as Maya/Max and/or altered used properly in Nuke/Fusion

Thanks much for the help !


I have the same need/problem. I am using Unreal to render animation to video, so I don’t need to rely on the real time motion blur that the engine uses. Also, this motion blur tends to generate some unwanted artifacts and in general not to look realistic with very fast moving objects or rotating objects like wheels. I would much rather generate the motion blur in a proper post-processing suite like after effects or nuke. For that to happen I would need to render out a motion vector pass.

I tried to generate a post-processing material but I cant find a way to access the velocity of the vertex. Maybe possible with some custom glsl? Is there a way to do set up a motion vector pass from within the material editor?

Thank you very much.

Maybe you could just edit Motion blur pass to output that information.

Hello, Jenny,

Do you have an idea how I could do that? I am in a content only project and dont really know much c++. I would really appreciate some help. I noticed that on the engine content there is actually a RenderMotionVectors material, but it is designed and used for flipbooks, and seems to take advantage of the fact that the previous and current frame are stored on the same texture. I didn’t know that you could edit the motion blur pass, my approach was using a post-process material that would need some way to access the velocity buffer on the current and previous frame, and then maybe use some of the logic of the flipbook material to get the color values right.

Thank you!