Interpolation Styles

A model's interpolation style determines the method of interpolation a renderer uses when applying lighting or other shading effects to a surface. QuickDraw 3D defines constants for the interpolation styles that are currently available.

typedef enum TQ3InterpolationStyle {
    kQ3InterpolationStyleNone,
    kQ3InterpolationStyleVertex,
    kQ3InterpolationStylePixel
} TQ3InterpolationStyle;


The constant kQ3InterpolationStyleNone specifies that no interpolation is to occur. When a renderer applies an effect (such as illumination) to a surface, it calculates a single intensity value for an entire polygon. This style results in a model's surfaces having a faceted appearance.

To render surfaces smoothly, you can specify one of two interpolation styles. The constant kQ3InterpolationStyleVertex specifies that the renderer is to interpolate values linearly across a polygon, using the values at the vertices. The constant kQ3InterpolationStylePixel specifies that the renderer is to apply an effect at every pixel in the image. For example, a renderer will calculate illumination based on the surface normal of every pixel in the image. This rendering style is likely to be computation-intensive.

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© 1997 Apple Computer, Inc.

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