Archive for the 3D Development Software Category

Radiosity and Raytracing

Posted in 3D Development Software on June 26, 2008 by angelus13

Radiosity takes into account all indirect lighting in the room as well as direct light so that any shadows that are cast are softer becase the indirect light will change the shadow’s cast but standard lighting deals in purely in direct lighting (see example:), as a result standard light isn’t realstic it just shows a single direct light from a chosen light source well Radiosity will show a very realistic lighting just like real life.

 

 

radiosity_comparison.jpg

the strenth of the of the light is specified in photometric units (lumens, candelas and so on).

the left image contains no radiosity, there is lighting but it’s very simple lighting. there right image contain radiosity, if you noticethe shadows look alot softer and the lighting looks alot brighter. Radiosity does have some weaknesses it changes with sudden changes in visiblity and hard edged shadows. the up side to radiosity is it looks alot more realistic, the main problem with radiosity is the time it takes to render is immense.

 

 

Ray Tracing

Ray Tracing is a global illumination created around a randering method.when the rays of light hit an object one of 3 things can happen absorption, reflection and refraction. Ray-tracing mimics this. It traces rays of light from the eye back through the image plane into the scene.

 

Ray-tracing and radiosity work together, and help cover each others disadvantages. Radiostiy is good with diffuse-to-diffuse inter-reflections. Its disadvantages are that its 3d mesh takes up memory and it doesn’t account for specular reflections. Ray-tracing is good with rendering specular reflections. Its disadvantages are that it takes long amounts of time and it doesn’t account for diffuse reflections.

 

 

 

 

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