GPU Pro 5

30 I Rendering

B

RRR

G

G

G

BB

bc2

bc1

bc1

bc2 bc2

(0,0,0) (0,0,0) (0,0,0)

Figure 2.3. Hue encoding process

in Figure 2.3 and can be outlined as follows:

1. Project the color point in the linear RGB space onto the color plane.

2. Compute the 2D coordinates of the point on the plane.

3. Find a 2D line on plane passing through (0,0,0) and the point.

4. Find the proportion in which the line crosses the 2D line between the base

color points, i.e., determine the blend factor for the base colors.

The first step is a simple geometric operation. From the second step on,

we have to perform geometric operations on 2D coordinates embedded within

the plane. Having the two base ...