The following conditions are required to experience the issue:
- Depth buffer write is disabled
- The z coordinates of vertices in the vertex shader is outside the [0,1] range
- gl_FragDepth is updated in the fragment shader
Under these conditions, the geometry is not drawn.
Intel Iris Plus Graphics 640 with driver 126.96.36.19912
Based on The Practical Approach to Vulkan sample 1. I just added a bias to the z coordinate of vertices, disabled depth writes and added a line in the fragment shader to update gl_FragDepth. In this configuration, nothing is drawn.
Enabling depth buffer writes makes the geometry appear.
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