I have a 3d tile map made up of individual billboards in OpenGLES. Each is a 2 triangles mesh and has a 3D Vector to determine its position and another defining its rotation from the origin at (0,0,0). Im trying to work out how to rotate the entire tile map around a point be that the origin or some arbitrary point in space. Im guessing i need to set up a Model Matrix instead for each tile. Then set up a world matrix for the world. Then on updating i would translate the world matrix and change the orientation and multiply it with each model matrix before rendering. Is this correct ?