Final Project Submission

We have implemented the following features in our WebGL path tracer:

• Diffuse
• Diffuse reflection
• Refraction
• Fresnel
• Anti alias
• Camera interactivity
• Subsurface scattering(although not very accurate)

Source code location: code
Web links:

• Basic path tracer
• Subsurface Scatter
• Fresnel

Video:

Paper: WebGL path Tracer Paper

Fresnel

This is a path tracer implemented in WebGL. This instance of path tracer displays fresnel equation implementation. It also allows camera motion on mouse click movements.

Fresnel
Fresnel equations describe the reflection and transmission of rays through an object. In essence, when the rays reach the boundary of two different materials then part of the wave is reflected and part is refracted. We use Russian roulette technique which determines either to refract or reflect based on the fresnel transmission coeffi- cient.
The direction of reflected ray is computed based on the laws of reflection, and the direction of refracted ray follows the Snell’s law with respect to the incident angle.

Subsurface scatter

Final presentation tomorrow

This is the path tracer written in WebGL.
To run the code: (actually it is still running)
1. click the mouse and change the position of camera by mouse motion.
2. Click again to stop camera movement.

Colors will accumulate and give the image.
Presentation: presentation
References:
http://madebyevan.com/webgl-path-tracing/
http://learningwebgl.com/blog/?page_id=1217
http://machinesdontcare.wordpress.com/2008/10/29/subsurface-scatter-shader/

Fresnel Refraction/reflection & subsurface scatteringRef

We implemented fresnel refraction/reflection and the results look great. Also, the accumulation is very fast. Here are some of the results of the rendering:

Reflection and refraction

SUBSURFACE SCATTERING

We tried to implement subsurface scattering using monte carlo method, but there was some problem the colors were getting translucent in the reflected image but not the actual object. Here, is the image representing this issue.

Incorrect SubsurfaceScattering

As you can see, the reflected image has the color that too not very good. since, we do not have enough time to fix that. We used the hack of sub surface scattering. The results seem OK.

Cool Images produced while trying to do subsurface scattering:

Glossy effect