Prototype terrain holes using stencils for better resolution
Create terrain only depth prepass (also stops unity overwriting stencil state) after HoleShape pass where stencil mask is written
Change terrain shader depth test to Equal (failing where prepass stencil test fails)
Change hole renderer to use cubes or triangle prism configs
Add HoleShape assets for minimal cube and triangle prism vertex positions and triangles
Dynamically duplicate HoleShape meshes (with vertexID based instancing) to meet min vertex count for efficient instancing
Improve HoleShape inspector with adjustable sliders