MeshCollider

MeshCollider - A level shape made of a mesh's triangles, which objects with collideLevel land on, slide along and walk up, as on a HeightMap: a level's floors, walls, ramps and rocks, often a low poly mesh made for collision

• It draws nothing: make an EngineObject3D with the same mesh to see it, or with a mesh of its own to show more than collides; Debug Physics on the debug overlay draws its edges
• An object collides with it as a capsule as tall as its height and as wide as its narrowest side, so it rides up a step lower than its round foot and over small bumps, and one with collideAsSphere3D as its sphere; a flat wide object, as a plank, is a sphere as thick as it is, at its middle, and its turn is not taken into account
• Its triangles are taken from the mesh in world space where it is, through its pos3D, rotation3D and scale3D, and taken again when it moves; call rebuild() after changing the mesh
• Any mesh works, a strip, an indexed one, a loaded model or one given its vertex data; both sides of a triangle collide
• A fast object is moved in steps no longer than half its radius, so it does not go through a thin wall
• Particles with collideLevel hit it, render3D.pick and the camera's wall test hit its triangles, both sides

const level = await loadOBJ('level-collision.obj');
new MeshCollider(level.mesh);