First pass:
Photon Map
Use the basic steps for ray tracing. The difference is using Russian roulette to determine the possibility of absorbing, reflecting and refracting. For the reflecting, using BRFD model.and refraction with Snell's law. Global map: Trace from light. Use projection maps to generate photons. Different light has different strategy for generating photons.
Caustic map: This map need a large amount of photons.
Second Pass:
Rendering Image
1 Direct Illumination: a ray is traced from the point of intersection to each light source. As long as a ray does not intersect another object, the light source is used to calculate the direct illumination2. Indirect Illumination: Use global photon map to estimate.3. Caustic Illumination: Use the caustic map4. Specular Reflection: Do as the ray tracing.
Use Photon Map to estimate radiance
From what I have got,
Targets are as follows:
1. Russian roulette function
2.BRDF model
3. Snell's law
4. Tracing the photon map
5. Gathering
However, the biggest problem is still that I have no computer to do it!!!!!! Frustrating..
