Spray Rendering From Wireframe

To spray render from Wireframe mode:

Select the Default Wireframe mode from the Display Modes tool.
Click the Spray Rendering tool on the Advanced Display palette.
Use the tool to paint over the area of your scene that you want to render.
Press the Spray Rendering tool again or press the Escape key to dismiss this render and return to Wireframe mode. This doesn't affect any previous render.