Creates the patch simulation and seeds every patch at its upright rest pose.
StaticcreateCreates a simple evenly spaced patch grid that covers the entire terrain.
Number of rows in the patch grid.
Number of columns in the patch grid.
Terrain width.
Terrain depth.
A list of patch descriptors.
Advances every patch by one frame.
The elapsed frame time.
The latest wind source state.
Total elapsed scene time.
Returns an immutable snapshot of the current states.
GrassPatchPhysicsSimulation implements a classic damped spring model. The spring continuously tries to pull the grass upright, damping removes energy over time, and the wind model adds external force.