"I want to implement an X-ray feature. Currently, I change the color of the selected mesh to red and apply an outline. Other meshes are set to transparent with applied opacity.
When I do this, as shown in the attached image, there are obscured parts. Can you provide example code or reference material for implementing an X-ray feature like this?"
You might also want to use depthTest, depthWrite and renderOrder. Here is a demo of a more stable x-ray-ish effect (i.e. elements do not pop-up or sink-down):
