About Gray

Gray (Greiners Raytracer) is a hobby/research project of mine. It is a program that simulates light to produce computer generated images. The technique used is called ray tracing, where a large number of rays are cast against mathematical 3D models to simulate the interaction between light and materials. The result is beautiful computer generated images, like the ones we are used to see in special effects in movies.

Path Tracing

ProgrammingPosted by Søren Greiner Wed, February 17, 2010 20:31:43
I started on a simple path tracing algorithm to learn a little about this method. Path tracing and bi-directional path tracing is the method that by far gives the most realistic looking images. However this is not the case with my implementation yet. Here is one of my first test images. For this image I traced 512 samples per pixel:

Fill in only if you are not real

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Posted by Søren Greiner Sat, February 20, 2010 20:10:22

Thanks! My path render is very primitive still. Actually I just implemented it to test the speed of my new KD-tree (which is about 30 times faster than my old ray tracer, mostly due to my old render being very slow for this kind of geometry).
For this image the light source is the entire hemisphere. So if my ray does not intersect any geometry I assume that the ray hit the sky.
Now I'm working on a better light model, so any object can act as an emitter.

Posted by D-POWER Sat, February 20, 2010 15:55:54

Nice render !What kind of light source did you used to illuminate this scene?Path tracing performs very well when the scene contains a big light source/sky.