static void AddCone(Camera camera, Vec3 from, Vec3 to, float radius)
{
Vec3 direction = to - from;
float length = direction.Normalize();
Vec3[] positions;
int[] indices;
GeometryGenerator.GenerateCone(radius, length, 32, true, true, out positions, out indices);
Quat rotation = Quat.FromDirectionZAxisUp(direction);
Mat4 transform = new Mat4(rotation.ToMat3(), from);
camera.DebugGeometry.AddVertexIndexBuffer(positions, indices, transform, false, true);
}