# Inspired from Clay Sculpting

If I want to create VR apps, I need to improve at 3D modeling.

For a good while ago, I stumbled upon Philippe Faraut's youtube clay sculpting videos. Watching the videos expose that he's picking shapes and masses that match close on what he is about to represent. The clay preserves the volume it has, so the way he lays out those clay masses resemble an anatomy of the model.

With computers I don't have modeling primitives that'd preserve their volume when merged. Most computer game models are just bunch of polygons forming surfaces. The surfaces still obey the anatomy of the model though.

Ben Mathis proposes picking shape primitives close to the shape you want to model. The method works for obtaining the overall shape of the character. The technique is very similar to clay sculpting, except that the shapes don't deform or squash to preserve their volume.

The concept of a "face normal" is important for the appearance of the polygonal shape. Normally the normal is calculated by interpolating the vertex normals, the vertex normals average from the polygons they connect to. Perfectly sharp edges are easy to obtain by edge splitting or flat shading them so that the normal just abrubtly bends at the crease.

But as graphics become more demanding we rather want smooth than crisp edges. The obvious approach is to form bewel edges.

The bewelled objects have additional polygons on the creases where the normals interpolate forming smooth edges.

Actually it is used everywhere. To get the normals correctly approximate the surface you want, you add more polygons into sharp turns everywhere.

It is common to organize surfaces into face loops. Many modellers tend to refer to this kind of 'wiring' as the topology. The loops form according to where they are needed.

In good models the point densities concentrate to where they are necessary. Organization-wise, you may want the individual loops to trace out important continuous details so they'd be easy to detail out. In this sense, the idea of the "topology" in polygon modeling comes from the anatomy of the model.