3D Graphics Programming with QuickDraw 3D 1.5.4

Normals

Labels

ASCII: Normal
Binary: nrml (= 0x6E726D6C )

Data Format



 
Vector3D            normal

normal: The surface normal at a vertex. This vector should be normalized.

Data Size

Description

The surface normal at a vertex of a verticed object is the average of the normals to the faces of that object sharing that vertex. This normal is obtained by normalizing the relevant face normal vectors, adding those vectors together, and normalizing the result. The surface normal vector is used in Gouraud shading calculations.

Parent Hierarchy

Element, attribute.

Parent Objects

Attribute sets. A normal always has a parent object.

Child Objects

None.

Example



 
Container (

    AttributeSet ( )

    Normal ( -1 0 0 ) 

)