PathTracer

I spent a lot of time trying to add direct light. But the result is not good. Frustrated.

Features now

 For the required features, I didn't have time to finish that by the deadline, although I just written the needed functions, and didn't debug them.
Optional features:
1. motion blur. I move the object according to time, and then blend those images together. The speed is changing with time.

2. Depth of field. Find the focus point, jitter the camera and then generate a new ray. The middle sphere is the focus. The near and further one become blur.

3. refraction. I use fresnel to calculate the reflection and refraction coefficient.

Limitations:The convergence speed is very slow.

Path tracing 1

Problem now, slow convergence speed. I am not sure whether I should divide the rendering equation into two parts, direct illumination and indirect illumination.  when I add direct illumination, the picture becomes very bright  eventually, without the direct illumination, the convergence progress seems very slow. The picture with direct illumination is warmer.

Corrected GPU Raytracing

I today found that my horizontal direction seems inverse from the others....I reverse the direction.Besides, i misunderstood the speculation formula, which leaded me to believe that only when material was reflective, it would have specular effects. I also correct this. Here are new pictures. Little change, looks much better now!hoho. I also change some parameters. Next time, I will definitely start make my demo earlier.My demo is really ugly and hasty for this time..T T

http://www.youtube.com/watch?v=voRr-dqSBTs&feature=player_embedded

I started to know that path-tracer is so powerful today. A lot of features could be down freely. Amazing
path tracing. HAHA. Looking forward to finishing the path tracer!!!