Module grass 

Procedural grass. The patch is split into square chunks; each chunk is one merged mesh with its own bounds, so the renderer frustum-culls whole chunks. Wind animation and distance thinning happen on the GPU in builtin:grass; the meshes are built once.

Chunks are Transient child entities: they never appear in the hierarchy or in saved scenes.

Structs

Grass

Seeded grass patch split into transient mesh chunks for frustum culling. Wind is animated by the grass shader; geometry is rebuilt when parameters change.

Constants

BLADE_TRIANGLES

Triangles per blade, both sides.

BLADE_VERTICES

Vertices per blade: four rows of two plus the tip.

Functions

chunk_grid

Grid of chunks covering the patch: (columns, rows).

chunk_mesh

Builds the blades of chunk (ix, iz); vertices are relative to the chunk centre.

update

Rebuilds changed grass patches and their transient mesh chunks.