Ok, this one is odd… but after going into work on my Technical layout details, when I get back to my main perspective window, the non-wireframe shading models are clipping along the XZ and YZ planes. I have clipping planes which are used in the layout viewports, but these are not them. In the case of the shaded render, the wireframe pass of the render is unaffected, but the solid pass is clipped. The Technical render of the layout is also affected in a similar way. It’s a little hard to describe, so pictures attached…
This might be related to this depth buffer issue, as it looks like it’s a render state that getting corrupted. I have a number of Technical display mode layout details, and fiddling with one can cause the others to either render correctly or not.
What’s odd is that this state persists back into the perspective editing window… and the only way to clear these mysterious clipping planes is to activate one of my normal clip plane objects in the perspective view which appears to reset the clip plane list.
This issue went away when I changed graphics cards. I suspect though, that it is related to the depth buffer issue mentioned above. That issue, along with non-existing block instances showing up at the origin, are all fixed by turning off “Show intersections” in the display mode options.