Levicky Outline

Eric-Levicky

Photon Mapping Outline

Subject to change

  • Introduction
    • How graphics are currently rendered in animated movies
    • Why Photon Mapping would be better
  • Body Section 1 (Use yafaray [ray tracer] as a comparison in this section)
    • What is Photon Mapping
      • Definition: “beam out rays from light source…”
      • Calculate all rays that are shot out of light source
      • Only use those rays that hit the camera
    • Benefits
      • Lighting effects that are now possible without being faked manually
      • Two Pass Method
    • Drawbacks
      • Takes a long time to render
      • Must pre-render
      • Wasted beam calculation on rays that never reach the camera
  • Body Section 2 – Ideas behind photon mapping
    • Photon Emission – how rays are emitted from each type of light source
      • Diffuse point light – point emitting light
      • Spherical light – sphere shaped light source
      • Square light – square shaped light source
      • Complex light – ameba shaped light source
    • Photon Scattering – how rays behave when they strike each surface
      • Absorbed
      • Reflected
      • Refracted
  • Body Section 3 – Methods needed in library for photon-mapper
    • Classes Needed
      • Point
      • Vector
      • Photon
    • Goal of each photon
      • Keep track of the power level and stop bouncing when it gets to a certain point.
      • Get the appropriate color of what it bounces off of (change power level)
    • Methods Needed
      • getColor()
      • getPower()
      • getFace() - gets the direction of the face of the object (for calculation of where the ray will bounce)
      • getAbsorbancy() - how much power is sucked up by a certain object (takes away from power)
      • bouncePhoton(Photon currentPhoton) - changes the angle, power, and color of the photon
  • Body Section 4 – Code Exploration
    • This section will contain methods I write for the ‘photon-mapper’ library
    • This section will only be code and a few comments; all explanations will be housed in ‘Body Section 3’.
  • Conclusion
    • Is the cost of photon mapping worth the reward?
    • Ray tracer can do miracles, show one of the images from the 'yafaray' project
    • Major benefit of photon mapping is that in a scene with unchanging light and no movement the camera can be moved without rendering anymore.