GPU Pro 6

302 IV Shadows

Figure 1.4. Contents of the translucency map: a red pole rendered from the point of

view of the light source.

this, nonintersecting lights’ shadows can be blurred in one pass, independently.

However, we also need to consider overlapping shadows from multiple lights.

We observed that this problem (blurring overlapping shadows) is essentially a

graph coloring problem, where each graph vertex color represents a shadow layer.

In each shadow layer, we store the data of several nonoverlapping lights. In this

graph, each light will be a vertex, and there will be an edge between two vertices

if the two lights intersect. Because determining the ...