Chapter 19: Controlling Shading
Table Of Contents
Chapter 19: Controlling Shading
Figure 19.1
A box with its normals indicated with arrows.
Shading Based on Normal Directions
Figure 19.2
Your headlight, like a miner's headlight.
Figure 19.3
A face shaded based on its orientation toward or away from the headlight.
Figure 19.4
A shaded face with its normal, a light source, a and a light line.
Figure 19.5
Shading variations based on a f ace's orientation toward a light source.
Figure 19.6
Shading variations based on the face's orientation toward a light source.
Determining Normal Directions
Figure 19.7
A triangle described by an indexed face set.
Figure 19.8
The right-hand rule for normals, the right-hand rules from the back of the face, and applying the right-hand rule to a more complex shape.
Figure 19.9
Two vectors computed for the triangle.
Figure 19.10
The V and W vectors computed for the triangle.
Figure 19.11
The normal for the triangle.
Understanding Smooth Shading
Figure 19.12
Four rectangles composing a half column's facets in outline form viewed from the front, shaded and viewed from the front, and in outline form viewed from above.
Figure 19.13
Using more facets to create smoother shading: four facets, five facets, six facets, and seven facets.
Figure 19.14
The shaded half column using normals that create a smooth-shading effect.
Smooth Shading and Normals
Figure 19.15
The top view of a half column built using four faces, and the top view of a perfectly rounded half column.
Figure 19.16
The top view of a half column with normals for each face in a faceted half column and pointing outward from the center for a perfectly rounded half column.
Figure 19.17
Comparing facet normals with the perfectly rounded half column's normals. Top view of normals pointing out from each coordinate of a face.
Figure 19.18
Comparing normals of facet coordinates and the perfectly rounded half column's normals, and corrected normals pointing out from each face's coordinates.
Figure 19.19
Comparing half-column shading : faceted, smoothly shaded and faceted, and smoothly rounded.
Computing Smooth-Shading Normals
Figure 19.20
The normals for a sine-wave shape.
Understanding Normal Binding
Understanding Normal Animation
The NormalInterpolator Node Syntax
The IndexedFaceSet Node Sytnax
The ElevationGrid Node Syntax
Experimenting with Normals
Figure 19.22
A square face with two normals pointing along the positive Z axis and two normals pointing along the positive X axis.
Smoothly Shading a Half Column
Figure 19.24a
A smooth-shaded half column using a crease angle. Compare with Figure 19.24b.
Figure 19.24b
Two half columns with a visible seam caused by inaccuracies in the crease-angle method of computing normals. Compare with Figure 19.24a.
Figure 19.25a
A smooth-shaded half column using custom normals. Compare with Figure 19.25b.
Figure 19.25b
Two half columns without a visible seam. Compare with Figure 19.25a.
Smoothly Shading an Elevation Grid
Figure 19.26
An elevation grid using a special shading effect.