The objects contained within the scene (houses, trees, cars) are often designed in their own object coordinate system (also called model coordinate system or local coordinate system) for reasons of simpler modeling. To assign these objects to coordinates in the world coordinate system or global coordinate system of the entire scene, the object coordinates are transformed by means of translation, rotation or scaling. This is done by multiplying the corresponding transformation matrices. In addition, several differently transformed copies can be formed from one object, for example a forest from a tree; This technique is called instancing.