Lerping between sprite frames means drawing two coplanar quads blended the right way. This is not something ray tracing can accommodate easily for all blending modes.
Disable lerping for now
Instead of passing model color around as an implicit global state, pass it per-model.
This makes it (a) easier to track, (b) easy to fix blending issues. E.g. this fixes incorrect coloring of brush and studio models, which is also different.
still not fully there:
- glow is slightly off
- TransAlpha has wrong blending mode
apparently pipeline settings for brushes, models, and sprites are substantially different, need different pipelines