The 3D render preview tab unveils what makes Digital Pipe Fitter so easy to use. You get to see exactly what your physical joint will look like when complete.

Holding the left mouse button and dragging it around the screen will spin the 3d rendered joint so you can view it from all sides. Holding the shift key on the keyboard while holding the left mouse button will pan the image around the screen.

The in/out slider zooms in and out. Holding the right mouse button and moving the mouse forward and backward will also control the zoom of the 3D preview.

If more than one component is shown on the 3d preview, the asm/exp slider assembles and explodes the assembly so that you can see how the components of the physical joint go together and view the inside structure of the joint. Holding the shift key on the keyboard while holding the right mouse button will allow control of the distance between components with mouse movement.