Deferred Lighting
Deferred lighting (also known as Light Pre-Pass) is a modification of the Deferred Shading. This technique uses three passes, instead of two in deferred shading. On first pass over the scene geometry, only the attributes necessary to compute per-pixel lighting (irradiance) are written to the G-Buffer. The screen-space, “deferred” pass then outputs only diffuse and specular lighting data, so a second pass must be made over the scene to read back the lighting data and output the final per-pixel shading. The apparent advantage of deferred lighting is a dramatic reduction in the size of the G-Buffer. The obvious cost is the need to render the scene geometry twice instead of once. An additional cost is that the deferred pass in deferred lighting must output diffuse and specular irradiance separately, whereas the deferred pass in deferred shading need only output a single combined radiance value.
Due to reduction of the size of the G-buffer this technique can partially overcome one serious disadvantage of the deferred shading - multiple materials. Another problem that can be solved is MSAA. Deferred lighting can be used with MSAA on DirectX 9 hardware.
Read more about this topic: Deferred Shading
Famous quotes containing the word lighting:
“Popular art is normally decried as vulgar by the cultivated people of its time; then it loses favor with its original audience as a new generation grows up; then it begins to merge into the softer lighting of “quaint,” and cultivated people become interested in it, and finally it begins to take on the archaic dignity of the primitive.”
—Northrop Frye (b. 1912)