Graphics Reference
In-Depth Information
13. In the completed project, the
Backspace
key is mapped to toggle between the
renderers. The following screenshot shows the Bezier output:
Bezier patch with integer partitioning and tessellation factors from top to bottom of: 1.2, 2.0, and 12.0
How it works…
In this recipe, we use bicubic interpolation of Bezier patches (for a
quad
domain with 16
control points), which can be used as a method for approximating Catmull-Clark subdivision
surfaces (Loop and Schaefer 2008).
The bicubic Bezier surface consists of four rows of Bezier curves using four control points
each. The interpolation across the Bezier surface works by first linear interpolating (lerp)
each of the Bezier curves, and then linear interpolating the results of these four curves.
The following diagram shows how this works for a single Bezier curve with a lerp value of 0.5:
