GPU Pro 6

4. Real-Time Rendering of Physically Based Clouds Using Precomputed Scattering 161

Figure 4.9. Sample refinement takes cloud transparency into account.

and distance to the cloud to attenuate the light samples along the view ray (please

refer to [Yusov 14b] for more details).

One important missing detail is sample refinement (see [Yusov 14a]), which

needs to account for screen-space cloud transparency. When computing coarse

unoccluded in-scattering, we take the screen-space cloud transparency and dis-

tance to attenuate the current sample. This automatically gives the desired effect

(Figure 4.9) with a minimal increase in performance cost.

4.6 Results