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Introduction Features

Techniques

Rendering Equation Conclusion

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Rendering is the process of generating an image from a model, by means of a

software program.

The results of such a model can be called a rendering.

The model is a description of three dimensional objects in a strictly definedlanguage or data structure. It would contain geometry, viewpoint, texture and

lighting information. The image is a digital image or raster graphics image.

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A rendered image can be understood in terms of a number of visible features.

shadinghow the color and brightness of a surface varies with lighting

texture-mappinga method of applying detail to surfaces

fogging/participating mediumhow light dims when passing through non-clear

atmosphere or air

shadowsthe effect of obstructing light

soft shadowsvarying darkness caused by partially obscured light sources

reflectionmirror-like or highly glossy reflection

transparencysharp transmission of light through solid objects

translucencyhighly scattered transmission of light through solid objects

refractionbending of light associated with transparency

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indirect illuminationsurfaces illuminated by light reflected off other surfaces,

rather than directly from a light source (also known as global illumination)

caustics (a form of indirect illumination) reflection of light off a shiny object,

or focusing of light through a transparent object, to produce bright highlights on

another object

depth of fieldobjects appear blurry or out of focus when too far in front of or

behind the object in focus

motion blurobjects appear blurry due to high-speed motion, or the motion of

the camera

non-photorealistic renderingrendering of scenes in an artistic style, intended

to look like a painting or drawing.

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1. Scanline and Rasterization rendering- geometrically projects objects in the

scene to an image plane, without advanced optical effects;

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Ray Casting- considers the scene as observed from a specific point-of-

view, calculating the observed image based only on geometry and very

basic optical laws of reflection intensity, and perhaps using Monte Carlo

techniques to reduce artifacts.

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Ray Tracing-is similar to ray casting, but employs more

advanced optical simulation, and usually uses Monte Carlo

techniques to obtain more realistic results at a speed that isoften orders of magnitude slower.

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It serves as the most abstract formal expression of the non-perceptual aspect of

rendering. All more complete algorithms can be seen as solutions to particular

formulations of this equation.

At a particular position and direction, the outgoing light (Lo) is the sum of the

emitted light (Le) and the reflected light. The reflected light being the sum of the

incoming light (Li) from all directions, multiplied by the surface reflection and

incoming angle. By connecting outward light to inward light, via an interaction

point, this equation stands for the whole 'light transport' all the movement of

lightin a scene.

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Rendering Equation

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