I set up in Blender 2.8 to do some lip-sync with a very small reference movie file (1.95 Mb - 640x360resolution) The reference movie plays perfectly in preview at 25FPS when I have added keyframes on my shape keys for phonemes at frame 1 - (No animation yet just a keyframe for each mouth shape at 0%) The problem is that as soon as I add one keyframe on the characters Jaw bone in the rig, I then only get the reference movie playing at 4FPS. If I dont add the Jaw bone keyframe the reference plays at 25FPS no problem but as soon as this one bone on the rig has a LocRot keyframe I’m crawling at 4FPS. Does anyone know why this is or a fix for it. This is my usual set up for lip-sync, done it many times without a problem but not today!
Have you tried similar setup in 2.8 ?
The cause is obvious, moving a bone force the mesh to update and that slow down blender.
Even if you change the sync time in the timeline you’ll have dropped frames.
If you have several meshs deformed by the armature , check their modifiers and/or try to hide-viewport them ( the computer screen icon, not the eye) .
That may smooth things up a little bit !
You had Subdivision Surface enabled, disable it and only enable it for render, otherwise the computer will calculate each position since the modifier will work on it each frame, but this goes for every modifier, they calculate each position for each frame, try to disable or apply as many as possible.
