In our last lesson, we considered a novel approach to subdivision surface model in 3D Studio MAX which I have found extremely useful. I noted at the end of that lesson that this approach sacrifices one of the three ideals of subdivision surface modeling in that you cannot see the control mesh and the subdivision surface at the same time.

David Innis, a reader, wrote to remind me of the old (pre-MAX 3) technique for solving this problem. Prior to the arrival of MAX 3, you couldn't see control mesh and the subdivision surface at the same time when using MeshSmooth, even on an Editable Mesh object. MAX users commonly used a reference object to work around this problem. This is no longer necessary in MAX 3 when using an Editable Mesh, and I completely forgot about it. But this technique can be resurrected to create a complete subdivision surface setup when using an Editable Patch object. It's a bit of a hassle, but it's worth the trouble.

Here's the idea.

We are building a character figure. Like all bilaterally symmetrical objects, it is best to model only a single half and rely on mirroring to generate the other side. In the first image, we see a parametric Box object converted to an Editable Patch. As explained in the previous lesson, we create what is functionally a polygonal mesh by reducing the number of View Steps to zero, and filtering out the selection of the Bezier handles. By adding a vertical edge down the middle, and deleting one half of the model, we are left with only the other half, open along the vertical centerline. Note how the bottom of the centerline is precisely at the center of world space. This makes it much easier to mirror the object.

In the next image, the object is assigned a wire material in the Material Editor to make sure it displays in wireframe. You may also choose, as I did here, to make the material "2-sided," so that all of the edges are visible from all angles. This creates the cage or control mesh. Create a clone of this object in the Edit menu and make it a reference object. As a reference, the new object will update to follow all of the edits of the control mesh, but can also receive unique modifiers of its own. Put a MeshSmooth modifier on the reference object and give it a couple of smoothing iterations. Assign this subdivision surface object a different (non-wire) material so that you see it smooth shaded within the wire control mesh. The Edged Faces option in your viewport reveals the quad structure of the subdivision surface.

I'm used to seeing only half of the model as I work on it, but most people will want to see both halves. Select your subdivision surface and mirror it as an instance. Like so.