It looks like depth testing is not working for 2D objects that use a 3D transformation. To reproduce, run the following on the metal branch using the (default) MTL pipeline:

1. java -jar apps/toys/ColorCube/dist/ColorCube.jar

BUG: It will be rendered without depth testing

NOTE: this demo creates a "cube" out of 6 2D Rectangle objects with 3D transforms.

This works correctly on the ES2 pipeline.