In this tutorial, we will model a tetrahedron shape with a twist! You will need 3dsmax 2010 or higher. No addons or plugins are required. The techniques used here employ standard polygonal modeling techniques, and take advantage of the Graphite Modeling tools and real world units for creating an object which can be 3d printed, or used as a unique 3d asset to render.
Tutorial: Model A Twisted Tetrahedron Curio For 3D Printing