As I understand, you want to take a cube and change its shape so it looks like the combination of 2 intersecting 2-sided quads.
Assuming the cube is broken along the edges, you need to:
- Multiply the vertex normal with negative half cube edge length
- Connect the result to World Position Offset
Also, we’ll get rid of the top and bottom faces:
Since this is for grass, I guess you are already using a masked material. So, masking makes sense. You can multpily your current mask with 1-abs(Z component of vertex normal) to mask them.
