I wanted to provide an answer for this question I was struggling with. You have a model and armature with a high poly mesh. How do you lower the mesh poly count and apply the same animation to it? I got you covered, here is my personal method, proxy-free!
Basic Rundown: With the rigged high poly mesh, you will duplicate the mesh and rig, lower the poly count, animate with it, and then apply the animation from the low poly rig to the high poly rig.
- Make sure high poly mesh and it’s rig are all present in a collection.
- Duplicate the entire collection. Make sure to label the mesh, armature, and collection all as low poly to avoid confusion.
- Lower the poly count of the mesh. With your statistics enabled in the Viewport Overlays tab, go to Modifiers < Decimate, and lower the ratio until the model is safely around 20,000 triangles. Make sure the Decimate Modifier is above the Armature Modifier, and apply the Decimate Modifier.
- Animate and apply animation to high poly mesh rig: Now you can animate freely with the mesh not bogging down your system. Animate the low poly rig. In the Action Editor, label this animation as the low poly rig. Click on the armature of the high poly rig, locate the low poly rig animation, and apply it. Done.