Transformations

Hi, I think I have quite a gd understanding of Matrix transformations in 3D programming: Local Space - Mesh scaled/rotated around own matrix World Space - All meshes and other polygons translated to the world, then whole world roatated Camera Space - World rotated so that camera position is the orgin so easy to convert to 2D space Project Space - Convert from 3D space to 2D space ie the monitor Have I got the idea correct ? , if not could you correct me please Now if im thinking correct , won''t I don''t get is do you have to concanate Local Matrix for every mesh with with the world Matrix every time you draw a frame , if so won''t that be fcking slow ? thanx in advance WizHarD