Orthographic camera and the z-buffer

To demonstrate the issue, I’ve created a snippet in the playground: https://playground.babylonjs.com/#IDSQK2#77

Running the snippet shows three circles in various shades of gray. After uncommenting lines 27-31 to activate the orthographic camera, three circles appear but only in one color instead of the expected three shades of gray as with the default camera.

Is there a bug in the snippet or in the orthographic camera?

Thank you for your help.

Welcome aboard!

There are differences in z in ortho mode too, but it seems the values are too close to each other to see it visually. If you set the depth renderer to “non linear” mode, you will see the shades in ortho mode:


Even in linear mode you can make the shades visible in ortho mode if tightening the minZ/maxZ values according to the scene and changing the scaling of the color before display: