High-detail blocks in first-person have gaps in the meshes

[trigger-segfault]

Describe the issue

When in first-person view (which is the only time high-detail blocks are used). Crevices between the corners and connections of blocks can be seen, especially when they are far away from the unit. This looks awkward, as you can see slightly into the void (fog colour) through these gaps.

Cause

The source of this issue is an effect of scaling the Z dimension based on distance, which is done for unknown reasons. Many different transforms are applied on promesh (high-detail) blocks before they are rendered. The unintended consequences of this scaling are the gaps that form. However, the gaps are still slightly visible with this Z scaling disabled.

Attachments

Preview of how distance from a block changes the appearance of the crevices. They seem to close in, as the view closes in.

Rendering code was changed to showcase this more clearly in topdown view, but the same behaviour holds in first-person views.

OpenLRR_CrevicesBlockDistance_new.mp4