Luminosity

Luminosity is a simple and elegant ray tracer written in Haskell.

Dependencies

Before compiling, get Luminosity's dependencies.

$ cabal install json --ghc-options=-DMAP_AS_DICT
$ cabal install blaze-builder

Add --enable-documentation if you want their symbols to be linked when generating Luminosity's documentation.

If you already have JSON, make sure to --reinstall with the MAP_AS_DICT option, otherwise Luminosity won't compile.

Compiling

$ cabal build

The executable will be located in dist/luminosity.

$ cabal install

This will install Luminosity to your user's local cabal directory.

Documentation

$ cabal haddock --executables --hyperlink-source

Add --haddock-option=-ignore-all-exports to see documentation for all functions.

Running

$ luminosity Scene.json Image.tga

You can leave out the second argument (in this case the image would be written to Scene.tga).

Scene input

Rather than introducing some custom format, Luminosity uses JSON to describe a scene. JSON is easy to read and there are many existing validation tools.

To learn how to write scenes for Luminosity, check out the Sample scene and the Parse module.

Of special note, all colours and vectors are specified as 3-element arrays. Colour channels are floating-point (0.0–1.0, not 0–255). The width (and aspect ratio) of the camera is dependant on the resolution in the settings, while the height remains constant. Use ortho-scale to increase the size of an orthographic camera, and for perspective cameras, simply move it further back or adjust the focal-length.

Image output

For now, the image output format is uncompressed TGA (Targa) for its simplicity. Soon, it will be PNG instead.

Features

Current features

• JSON scene input
• TGA image output
• sRGB conversion
• orthographic and perspective projections
• sphere and plane primitives
• Lambert diffuse reflection
• ray traced reflection

Planned features

• PNG image output
• parallel rendering
• faster rendering (optimized Vector)
• anti-aliasing (supersampling)
• exposure operator (rather than saturation)
• Blinn–Phong reflection
• transparency and refraction
• Fresnel effect
• more Surfaces (Cubes, Cones, Cylinders, Metaballs)
• directional light sources
• depth of field
• procedural and bitmap textures
• bump mapping

License

© 2012 Mitchell Kember

Luminosity is available under the MIT License; see LICENSE for details.