GPU Pro 6

5. Real-Time Global Illumination Using Slices 277

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Valid Region’s Contribution to Irradiance

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Figure 5.7. Contribution of the valid region to irradiance when sampling beyond the

border.

5.4.6 Results

Before moving on, it’s useful to compare the approximation that has been de-

scribed, with the ground truth result.

Figure 5.8 shows the scene. The black square with the cyan circle is the emis-

sive plane, at y = 0. We’ll evaluate the irradiance at points on the transparent

square, which are the points −32 ≤ x ≤ +32, −64 ≤ y ≤ 0, z = 0. For simplicit ...