Procedural terrain generator and Grass Brush

Terrain: WASD control camera's movement, left Ctrl controls camera to move down,  space controls camera to move up, click right mouse button to lock the camera, the mouse wheel controls the FOV of the camera.

GrassBrush:  Press left mouse button to plant plants, press right mouse button to erase plants.

Press Esc to hide the UI.

PS: Because WebGL and WebGL2 do not support geometry shader, so I can only build a windows version of grass brush.