2011

Table Of Contents
When normals are unified and point in the same outward direction, the
renderer processes each face and renders the model. If any normals are flipped,
facing inward, the renderer skips them and leaves triangular or quadrilateral
holes in the rendered image.
In instances where you see a hole, it usually means one of two things: Force
2-Sided is turned off in the Render Settings palette or the face is physically
missing from the model.
If the face is actually missing, youll need to manually reconstruct it. The
direction of normals is determined by the way a face is drawn in a right-handed
coordinate system: if you draw the face counter-clockwise, the normals point
outward; if you draw the face clockwise, the normals point inward. You should
draw faces consistently.
NOTE Solid objects have meshes and normals correctly oriented, which can be
an aid to creating models for rendering.
When rendering, the renderer searches for all normals that point away from
the viewpoint and removes the associated faces from the scene. This removal
2104 | Chapter 46 Render 3D Objects for Realism