Fast Photorealistic Techniques to Simulate Global Illumination in Videogames and Virtual Environments
Abstract
To compute global illumination solutions for rendering virtual scenes, physically
accurate methods based on radiosity or ray-tracing are usually employed. These
methods, though powerful and capable of generating images with high realism,
are very costly. In this thesis, some techniques to simulate and/or accelerate
the computation of global illumination are studied. The obscurances technique
is based on the supposition that the more occluded is a point in the scene, the
darker it will appear. It is computed by analyzing the geometric environment
of the point and gives a value for the indirect illumination for the point that is,
though not physically accurate, visually realistic. This technique is enhanced
and improved in real-time environments as videogames. It is also applied to raytracing
frameworks to generate realistic images. In this last context, sequences
of frames for animation of lights and cameras are dramatically accelerated by
reusing information between frames.
Images and videos
Obscurances in videogames images
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Without obscurances or direct light |
Only Obscurances |
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Only direct light |
Obscurances and direct light |
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Without obscurances or direct light |
Only Obscurances |
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Only direct light |
Obscurances and direct light |
Obscurances in videogames videos
Obscurances with Color Bleeding video
3 cubes demo video. Presented at EUROGRAPHICS 2003 Video and Slide Show.
GPU Obscurances with Depth Peeling
We take advantadge of GPU graphic cards to accelerate the computation of indirect illumination of 3d scenes.
Obscurances for Ray-Tracing
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Kitchen with one light |
Kitchen with daylight |
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Kitchen vase closeup |
Kitchen closeup |
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Aircraft cabin |
Another illumination |
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Another view |
Stairs |
Light animation with obscurances
Reuse of hits: videos
- Hit reuse animation (divx) in kitchen model (biased, Havran et Al.), 2 seconds, reuse of 7 frames, 800*600 pixels, 36 hours rendering
- Hit reuse animation (divx) in kitchen model (unbiased), 2 seconds, reuse of 7 frames, 800*600 pixels, 40 hours rendering
- Hit reuse animation (mpg) in kitchen model (biased, Havran et Al.), 2 seconds, reuse of 17 frames, 320*240 pixels, 15 hours rendering
- Hit reuse animation (mpg) in kitchen model (unbiased), 2 seconds, reuse of 17 frames, 320*240 pixels, 16 hours rendering
- Hit reuse animation (mpg) in kitchen model (unbiased), 12 seconds, reuse of 17 frames, 320*240 pixels, 140 hours rendering
Reuse of hits: comparing images (frame 24, small)
Middle frame without reuse.
Middle frame with Havran et Al. (biased) reuse. Note the noise for specular materials as the vase.
Middle frame with unbiased reuse.
Comparing images (frame 24, big, with noise)
Middle frame without reuse.
Middle frame with Havran et Al. (biased) reuse. Note the noise for specular materials as the vase.
Middle frame with unbiased reuse.
Frame Array: Simultaneous light and camera animation
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