GPU Pro 7

180 IV Mobile Devices

V

1

, V

2

– vertex/pixel to light vectors V´

1

, V´

2

– local corrected vectors

- - - Bounding

volume

V

2

V´

2

C

V´

1

L

V

1

Figure 1.4. Representation of local correction of a vector according to the cubemap

position and the bounding volume.

Output value:

Lp—the corrected vertex-to-light vector which needs to be used to fetch

a texel from the shadow cubemap.

There may be many other methods of correcting the vector. The one that we

used is listed in Listing 1.1.

// Working in the world coordinate system

vec3 intersectMaxPointPlanes =(BBoxMax − V )/L ;

vec3 intersectMinPointPlanes =(BBoxMin − V )/L ;

// Find only intersections in the forward direction ...