Blender Model

Blender 3d is a free, opensource modeler that runs on both Windows and Linux. It can be downloaded from The application is not perfect (it can be difficult to represent scale) but it will get you a fairly realistic representation of what your project will look like, and how the parts will fit together.

As the render was for engineering purposes, I did not apply textures to the objects.

A 3d render of the cat tree