Topics covered in this Lesson: Setting and Using the UCS When working in 3D, it sometimes necessary to change the plane that you are drawing on. For example, if you need to add some detail to the side of a wall, you would want to draw on that plane. It's like taking a sheet of paper up off the floor (WCS) and taping it onto the wall (UCS). The WCS is the World Co-ordinate System. This is the way that the default X,Y and Z axes are directed when you begin a new drawing (X to the right, Y pointing up and Z pointing towards you). The UCS is the User Co-ordinate System. This is a ‘redirection' of the WCS based on parameters set by the AutoCAD user.

1. Difference Between Ucs And Wcs

Difference Between Ucs And Wcs

There are several ways of doing this, and we'll look at an example here. This is a simple shape drawn on the WCS with one corner located at 0,0,0. Here is the same object shown a new UCS based on the side of the object, so that you are able to draw on the side of the building - maybe to put a door in? Note the direction that the X and Y axes are now pointing. Notice that the positive X Axis is now pointing along side of the structure.