You can also click on the display modes button. That is the little box icon on the bottom right of the Bryce desktop above the +- magnifier buttons. Display has a third usefule mode. It shows a render and wireframe at the same time. Really useful if you need to reposition something and see how it rendered at the same time. Your project will open to the last saved render everytime you reopen the file. I just click on the left then the right corners of the view control to shift the view away then back to the current view and it automatically reverts to wireframe. Rochr and Jamonjay's work just as well but I thought I should mention the file always opens to a render not wireframe.