Mp2 global illumination
This presentation is the property of its rightful owner.
Sponsored Links
1 / 14

MP2: Global Illumination PowerPoint PPT Presentation


  • 108 Views
  • Uploaded on
  • Presentation posted in: General

MP2: Global Illumination. Advanced Graphics Rendering and Appearance Modeling Chris Lattner May 5, 2003. What I’ve done. Global Illumination: Specifically, chasing after caustics and other indirect illumination Local illumination model is simple (phong) Two approaches:

Download Presentation

MP2: Global Illumination

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Mp2 global illumination

MP2: Global Illumination

Advanced Graphics Rendering and Appearance Modeling

Chris Lattner

May 5, 2003


What i ve done

What I’ve done...

  • Global Illumination:

    • Specifically, chasing after caustics and other indirect illumination

    • Local illumination model is simple (phong)

    • Two approaches:

      • bi-directional raytracing

      • photon mapping

  • Built on my existing raytracer

  • All timings are on an 800mhz P3 laptop


Implementation details

Implementation Details:

  • Bi-directional Raytracing:

    • Deposit energy into texture map

    • Requires tweaking texture resolution

  • Photon Mapping:

    • Standard model, uses kd-tree for storage

    • No projection map, no irradiance cache

  • Both:

    • GI only used for indirect illumination

    • Raytracer handles direct illumination


Example results simple scene

Example Results: “Simple” Scene

  • 2 light sources

  • One “glass sphere”

  • One reflective sphere

  • One cylinder

  • Caustics:

    • Cardioid from cylinder

    • Two focusing caustics from glass sphere


Simple no global illumination

Simple: No Global Illumination

  • Render Time: 217 seconds (800x600)


Simple photon mapped result

Simple: Photon Mapped Result

  • Render Time: 436 seconds

  • 20,000 photons shot, 30 samples per pixel


Simple photon mapped result1

Simple: Photon Mapped Result

  • Render Time: 1344 seconds

  • 150,000 photons shot, 75 samples per pixel


Simple bi directional raytracer

Simple: Bi-directional Raytracer

  • Render Time: 402 seconds

  • 410 rays shot, 512x512 light map


Glass no global illumination

Glass: No Global Illumination

  • Render Time: 88 seconds (800x600)

  • Note lack of illumination in the liquid


Glass photon mapped result

Glass: Photon Mapped Result

  • Render Time: 524 seconds

  • 200,000 photons shot, 100 samples per pixel


Glass bi directional raytracer

Glass: Bi-directional Raytracer

  • Render Time: 124 seconds

  • 410 rays shot, 256x256 light map


Example results pool of water

Example Results: Pool of water

  • Photon mapped hole with bump mapped surface

  • Different bump map amplitude & frequency


Example results teapot caustic

Example Results: Teapot Caustic

  • Bezier patch model (but no bottom)

  • Photon mapped, note highlights on teapot


Overall impressions

Overall Impressions

  • Bi-di can give better results (and renders faster), if you’re willing to tweak it all day long

  • Photon mapping requires more optimizations (than I implemented) to make it practical

  • Photon mapping has better theoretical background, better as a framework for many extensions

  • My bi-di implementation is a big hack


  • Login