Определение сферы, в которую не могут заходить вершины. Это позволяет просчитывать коллизии с анимированой тканью.
The pair (collisionSphereRadius, collisionSphereDistance) define a sphere for each cloth vertex. The sphere's center is located at the position constrainPosition - constrainNormal * (collisionSphereRadius + collisionSphereDistance) and its radius is collisionSphereRadius, where constrainPosition and constrainNormal are the vertex positions and normals generated by the SkinnedMeshRenderer. The Cloth makes sure that the cloth vertex does not enter this sphere. As a typical usecase, set collisionSphereDistance to zero and collisionSphereRadius to a large value w.r.t. the triangle size. In this setup, the cloth collides against the skinned mesh. Default: 0.0 Range: [0,inf).