User Guide

259

If the style parameter is set to #flat, each vertex receives a normal for each face to which it

belongs. Furthermore, all three of the vertices of a face will have the same normal. For example, if

the vertices of

face[1] all receive normal[1] and the vertices of face[2] all receive normal[2],

and the two faces share

vertex[8], then the normal of vertex[8] is normal[1] in face[1] and

normal[2] in face[2]. Use of the #flat parameter results in very clear delineation of the

faces of the mesh.

If the

style parameter is set to #smooth, each vertex receives only one normal, regardless of the

number of faces to which it belongs, and the three vertices of a face can have different normals.

Each vertex normal is the average of the face normals of all of the faces that share the vertex. Use

of the

#smooth parameter results in a more rounded appearance of the faces of the mesh, except at

the outer edges of the faces at the silhouette of the mesh, which are still sharp.

A vertex normal is a direction vector which indicates the “forward” direction of a vertex. If the

vertex normal points toward the camera, the colors displayed in the area of the mesh controlled by

that normal are determined by the shader. If the vertex normal points away from the camera, the

area of the mesh controlled by that normal will be non-visible.

After using the

generateNormals() command, you must use the build() command to rebuild

the mesh.

Example

The following statement calculates vertex normals for the model resource named FloorMesh. The

style parameter is set to #smooth, so each vertex in the mesh will receive only one normal.

member("Room").modelResource("FloorMesh").generateNormals(#smooth)