Project Rembrandt: Difference between revisions

;Then comes the Lighting Stage, with several substages :

:*<u>Ambient pass</u>: the diffuse buffer is modulated with the ambient color of the scene and is drawn as a screen-aligned textured quad

:*<u>Sunlight pass</u>: a second screen aligned quad is drawn and a shader computes the view position of every pixel to compute its diffuse and specular color, using the normal stored in the first stage. The resulting color is blended with the previous pass. Shadows are computed here by comparing the position of the pixel with the position of the light occluder stored in the shadow map.

:*<u>Additional light pass</u>: the scene graph will be traversed another time to display light volumes (cone or frusta for spot lights, sphere for omni-directional lights) and their shader will add the light contributed by the source only on pixels receiving light.

:*<u>Fog pass</u>: a new screen aligned quad is draw and the position of the pixel is computed to evaluate the amount of fog the pixel has. The fog color is blended with the result of the previous stage.

:All lighting computations are accumulated in a single buffer that will be used for the last stage, in addition of the one computed by the Geometry stage.