Mental Ray Approximation Editor
5. Let's make sure everything looks good. In the render settings switch to Mental Ray and choose Draft for the Quality Presets. Also, turn on Progress Messages under the Translation tab. This forces Mental Ray to give feedback in the Maya Output Window, including the rendered triangle count. (This tutorial assumes the displacement maps are already applied and tweaked to their necessary heights).
6. Thats it. Check out the final render! To see the maps in action, watch the Quicktime!