RUNNING GENSHADE

The system runs in both artist directed and automatic scoring modes. In both modes, artists need to provide the system with their selection of pre-built example shaders and generation parameters. In interactive artist mode, the artist controls aesthetic evaluation and selection of shaders. In automatic mode, the system evaluates generated shaders by comparing their rendered images with target images. The system generates a wide variety of children shaders. The artist can view these children shaders as their images are being rendered. The system can also run in the background, results can be viewed later using the graphic interface.

GenShade uses steering to speed up the search in a certain direction. The basic idea is that if results are not satisfactory, generation parameters are used to widen the variations being produced. One the other hand, if results are somewhat satisfactory, a small change is needed. Using the automatic scoring mode, the target images are used as an additional tool to guide the search in a certain direction.

Once one or more shaders have been selected to become the choice for this project, a fine tuning may be needed. GenShade provide such ability by simply selecting that shader and applying mutations, small random changes, to it. A large selection of shaders will be generated that are very similar to the original. The artist can then select the desired "cousin" of the original shader.

After GenShade generates a large number of shaders, the artist is given some decisions to make:
 

Select one or more of the shaders to become the final shader(s)

Send one or more shaders to be fine tuned,

Save the shaders to a new or existing database of shaders for future exploration,

Export the shaders as source code or compiled shaders.

Delete the unwanted shaders to preserve disk space.

GenShade makes artists' job much easier. For example,  an artist can provide the system with the required info and let it run over lunch time, or over night. Then come back, browse through a large variety of generated shaders, and pick the ones they want.

GenShade provides several pre-built example shaders to help get artists up and running quickly. It allows artists to easily customize databases of shaders. GenShade imports Cinema Graphics Inc.'s ShadeTree format. It exports shaders in RenderMan's shading language source code, Houdini V4.0's shading language source code and ShadeTree format. GenShade supports surface, displacement, light, and atmosphere shaders.
 

Artists can build their customized databases of shaders out of a mix of new generated shaders and prebuilt shaders. These new databases can be used for future projects.

If pre-built example databases are not enough, and artists would like to use shaders that they have collected over the years, there would be a need to convert these shaders into GenShade shader format. One method would be to use Cinema Graphics's ShadeTree software to rebuild the shaders and then import them into GenShade. Another method would be to use a text editor to modify the shader language text into GenShade format.  Artists would then make a database of their favorite shaders in different formats. The time spent on shader rebuilding would be highly rewarded given the fact that thousands of new diverse shaders may be generated from this initial database of shaders.
 

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Copyright (c) 1999 Genetic Graphics Inc. All Rights reserved.