Additional light pass: 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.The fog color is blended with the result of the previous stage.

Fog pass: a new screen aligned quad is draw and the position of the pixel is computed to evaluate the amount of fog the pixel has.Shadows are computed here by comparing the position of the pixel with the position of the light occluder stored in the shadow map. The resulting color is blended with the previous pass. Sunlight pass: 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.Ambient pass: the diffuse buffer is modulated with the ambient color of the scene and is drawn as a screen-aligned textured quad.

Sky pass: the sky is first drawn using classical method.

Then comes the Lighting Stage, with several substages There will be one texture for every light casting shadows. Next stage is the Shadow Stage we render the scene again into a depth texture from the point of view of the lights. On the contrary, deferred rendering is about separating operations in simplified stages and collecting the intermediary results in hidden buffers that can be used by the next stage.įirst stage is the Geometry Stage we render all the scene into 4 textures, using multi render targets, to do it in one pass: one for the depth buffer, one for the normals (lower left of the image), one for the diffuse colors (lower right) and one for the specular colors (upper right). Main view with the content of buffers displayed at corners ) in fragment passes on that buffer (or any others).įorward = (usually) rendering part of the shading (typically ambient and diffuse light) per vertex, extrapolate all quantities which are declared as varying across triangles and hand them via rasterizer to the fragment shader which does the rest This project is about changing the way FlightGear renders lights, shadows and shades, and aims at making Rembrandt painting style possible in FG.ĭeferred = rendering a geometry pass into the geometry (g-)buffer which holds positions, normals, materials, then doing all operations (texel, light. Rembrandt was a dutch painter living in the 17th century, famous as one of the master of chiaroscuro.

7.4.3 Performance and compatibility considerations.

7.3 Making sure that all geometry will cast shadow.

7.2 Registering all translucent surfaces.

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