Houdini has an example project from GDC 2017 showing vertex animation driven by texture data. Pretty cool! But it’s also possible to do this type of animation using alembic in UE4. If you’re unfamiliar with alembic, it’s basically a big geometry cache. You can’t interact with it, but it’s good for cinematic fx.
My question is, what’s the performance difference here? According to the comments in the first video, vertex animation via textures is
“Orders of magnitude faster. Alembic (in it’s current implementation) regenerates the mesh every frame, with this technique the mesh is already generated and you’re just updating the positions”.
But I’m still skeptical because pushing polys is typically not the bottleneck, whereas texture memory is always in short supply. Plus, I’m not sure what optimizations, if any, UE4 is doing under the hood to optimize alebmic playback.