Within a 3D scene, Impact has a concept of two types of coordinate systems. A world (or global) coordinate system and user coordinate system.
When viewing a 3D scene from the 'front', the world (or global) coordinate system could be considered as utilising the Y-axis as the vertical dimension, the X-axis as the horizontal dimension and the Z-axis as the depth dimension (i.e. 'into' the monitor, 'away' from you).
The user coordinate system is a user-defined coordinate system, for folding models only, in which the coordinate system may be aligned to any face and edge on a model.
Tools described in this section:
> User Coordinate System
> Object Coordinate System