[Figures 26 & 27] The surfaces were detached (left) to create a network. The final surfaces (right) were created from the patch network.

5. Once the surfaces had the approximate flow of geometry going in the right direction and position, the surfaces were detached to create a network of surfaces (Figure 26). From this point, the model can be approached as a patch model.

6. Patch surface alignment tools and techniques were used to get the surface network created in the previous step to become the final surfaces shown in Figure 27. To create and maintain isoparm alignment and tangency, attach, detach and rebuild surface tools were used extensively. While this part of the process is taking place, it is important to keep looking at the reference material. While using attach and detach, it is very easy to stray away from the actual shape of the reference material.

[Figures 28 & 29] The surfaces (left) were cleaned up. The final body model (right) for Dino.

7. The surfaces were aligned and smoothed. Any gaps between surfaces, and non-tangent conditions were cleaned up (Figure 28). Detail in the hips and shoulders were added to match the detail in the maquette.

8. The final surfaces for the body, shown in Figure 29, show the addition of the feet. The detail in the hips and shoulders was smoothed out due to issues that arose during animation setup. These wrinkles were added later during animation when the scene called for wrinkles.

Surface Settings
Because we have used surfaces that align on all sides, and have all of the isoparms that align, the surface to polygon conversion is very straightforward. You should, however, make all the surfaces single-sided, and make sure all of the surfaces are facing the right direction.

Low-Resolution Polygon Settings
There are two ways to control polygon conversion for creating polygon models from NURBS surfaces. One is to modify the settings in the Convert NURBS to Polygon option box. Start with General settings and select the Per Span # of Isoparams in 3D option. For a low-resolution model, the best setting would be one polygon per span. A mesh this low can be used for a wrap deformer as well.

Another way to control the resolution of a low polygon mesh created from a NURBS model is to copy all of the surfaces into another group, then rebuild all of the new surfaces to a lower resolution. Once this new lower resolution model is created, the same NURBS to Polygon settings described above can be used to create an even lower resolution mesh.

Sometimes NURBS models are used to create low-resolution “proxy” models that are later turned into subdivision models. The process to create a detailed character using this process for subdivision modeling is described in Chapter 13. These settings could also be used to create a low-resolution model for animation and to create a wrap deformer.