Why does my camera vibrate when using blendables?


I’m currently experimenting with rendering AOVs out of Unreal using a number of post-process materials on a Matinee camera, to help comping pseudo-realtime CG together (think, depth, normals, WS position etc).

However, when I apply one of my AOV materials to the camera, it begins to vibrate. This obviously isn’t helpful, since it means the passes won’t line up with the primary once they go into comp.

Any ideas what’s causing this?

If I set the blendable location to Before Tonemapping, the vibration goes away.

My guess would be that this is somehow related to temporal AA (antialiasing). It shifts the pixels around to come up with a softer edge by blending them over time but it seems in some rare cases you can break the smoothing/blending part of it from working.