Model Silhouette is wrong when silhouette alpha is not 1

[jjspace]

What happened?

Reported on the forum: https://community.cesium.com/t/behavior-of-entity-model-silhouette-color-options-with-alpha/37082

It seems this may have started happening in version 1.121

simplescreenrecorder-2024-12-05_15.02.40.mp4

It looks like something about the model is not getting translated correctly when it's rotated while processing the silhouette color. Could this be related to #11067?

Reproduction steps

1. Load the 3D Models Coloring sandcastle
2. Set the model color to white to avoid confusing the colors
3. Change the Silhouette alpha to anything lower than 1

Sandcastle example

No response

Environment

Browser: Chrome
CesiumJS Version: 1.124
Operating System: Linux

[ggetz]

Given the post processing depth buffer ties, perhaps #7705 is related?