I’m currently experimenting with mental mill and 3dsMax. mental mill is developed by mental images and is basically a graphical interface for developing mental ray shaders. You drag and drop the lines to join bubbles together, and underneath mental mill does all the coding.
Once you’re finished you can load the mental mill shader in 3ds Max 2010 and use the new viewport hardware shading to view your shader directly in the viewport. The autodesk guys have worked hard to ensure that this great viewport result is very close to the software rendering that mental ray does.
http://www.mentalimages.com/index.php
download the latest version and watch the introduction videos to get started.