WebGL2 Ray Tracing - 'realtime' ray tracing in a browser

This is a fairly basic (and currently proof of concept) ray tracer written in an opengl fragment shader.

Shader is hosted by a renderer written in javascript (or C++ in the prototypes dir).

A live version should be available on my website

Before viewing the page I recommend:

• That you have a decent graphics card - Anything above a NVidia GTX 950 should suffice
• That you use chrome, or other fast browser (You need WebGL2 support as a minimum, firefox works but is slower)
• That you save your work, and close any videos/games you've got open already

Current status / next steps

I've got this to a point where it could be useful, but mainly it's a side-effect of me learning the concepts. Watch this space if you like but I don't expect rapid development on this.

General TODO list:

• The code is a bit of a mess, general tidy needed
• Need to implement refraction (changing direction of ray in current 'transparency' calculation)
• Need to rework the shader interface, currently around 12 floats are wasted per primitive, and there's no checks on the shader uniform limits before compiling shaders
• Need to move the scene definition out into a file format, json or similar
• Need to move the primitive functions out - Should be possible to inject a new primitive type as a glsl function, without a shader rewrite
• Docs, docs, and more docs (If anyone else wants to read the code that is)

Primitives

Currently only spheres and planes are supported, but the interfaces should be extensible enough for new functions.

Shader Interface

The shader setup is fairly messy and inefficient at the moment, but boils down to

• Some #defines to enable components of the ray tracing algorithm
• A set of limits defined in the shader - Maximum number of reflections/similar
• A set of hard limits on the number of primitives, materials, and lights
• A UBO containing the primitives, materials, lights, and set of uniforms to setup the shader

Performance / Hardware supported

So far testing has been limited, mostly performed on Linux, NVidia Quadro M2000, running the proprietary drivers. A rough benchmark here is 25-30fps for an 800x800 pixel window. Performance is slightly lower in the browser, so the browser version is set to render at a lower resolution.

Some testing was performed on an Intel 530, but the performance is not acceptable at the moment (Will need heavy resolution scaling / a small canvas)

Thanks / Credits

Various sources were used to implement this, but a large credit goes to the book "The Ray Tracer Challenge" by Jamis Buck. I didn't follow it that closely in the end but it's well written, and covers the concepts in a clear manner.