   Matrix notation
  In one book for 3D graphics this is equation for combining transformation:Pworld = PobjectMobject -> worldCan someone explain me what does this mean beacuse I don''t know math so well. 
  Pworld = PobjectMobject -> worldDoesn''t do anything but set whatever Pworld is too PobjectMobject->world. But if Pworld is then set as DX''s world matrix then it will move PobjectMobject where ever it is the the matrix PobjectMobject->world once it is drawn. Which is probably just a translation-rotation matrix.It might seem strange to set the world matrix as each object is drawn but moving an object against a world is relative to moving a world against an object.