Real-Time Rendering, Third Edition, 3rd Edition

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590 13. Curves and Curved Surfaces

Figure 13.12. One method of computing the tangents is to use a combination of the

chords (left). The upper row at the right shows three curves with different tension

parameters (a). The left curve has a ≈ 1, which means high tension; the middle curve

has a ≈ 0, which is default tension; and the right curve has a ≈−1, which is low tension.

The bottom row of two curves at the right shows different bias parameters. The curve

on the left has a negative bias, and the right curve has a positive bias.

The top row at the right in Figure 13.12 shows different tension pa-

rameters. The default value is a = 0; higher v