World orientation in OpenGLES clarification

Question

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 ?

Answer 1

I think i have figured it out, though my terms where wrong i meant projection matrix when i said world matrix.

So the projection matrix is transformed and reoriented. This is then multiplied to all of the world objects " Model matrices ". They are re oriented accordingly (which works fine). To follow a player the " Projection Matrix " and the players " Model Matrix " are similar so you follow the player with the right offsets so the projection matrix is set just behind a player for say third person perspective.