Photon Mapper

This plugin implements the two-pass photon mapping algorithm as proposed by Jensen [21]. The implementation partitions the illumination into three different classes (diffuse, caustic, and volumetric), and builds a separate photon map for each class.
Following this, a standard recursive ray tracing pass is started which performs kernel density estimation using these photonmaps. Since the photonmaps are visualized directly, the result will appear “blotchy” (Figure 36) unless an extremely large number of photons is used. Asimple remedy is to combine the photon mapper with an irradiance cache, which performs final gathering to remove these artifacts. Due to its caching nature, the rendering process will be faster as well.
When the scene contains participating media, the Beam Radiance Estimate [20] by Jarosz et al. is used to estimate the illumination due to volumetric scattering.

Remarks:
• Currently, only homogeneous participating media are supported by this implementation

Parameter

  • Max. path depth : integer
    • Specifies the longest path depth in the generated output image (where -1 corresponds to ∞). A value of 1 will only render directly visible light sources. 2 will lead to singlebounce (direct-only) illumination, and so on. (Default: -1 -> 24 @ blender)

  • Russian roulette starting depth : integer
    • Specifies the minimum path depth, after which the implementation will start to use the “russian roulette” path termination criterion. (Default: 5 -> 10 @ blender)

  • Direct Samples : integer
    • Number of samples used for the direct illumination component (Default: 16)

  • Glossy Samples : integer
    • Number of samples used for the indirect illumination component of glossy materials (Default: 32)

  • Global Photons : integer
    • Number of photons that will be collected for the global photon map (Default: 250000)

  • Caustic Photons : integer
    • Number of photons thatwill be collected for the caustic photon map (Default: 250000)

  • Volume Photons : integer
    • Number of photons that will be collected for the volumetric photon map (Default: 250000)

  • Lookup radius (global) : float
    • Maximum radius of photon lookups in the global photon map (relative to the scene size) (Default: 0.05)

  • Lookup radius (caustic) : float
    • Maximum radius of photon lookups in the caustic photon map (relative to the scene size) (Default: 0.0125 -> 0.01 @ blender)

  • Caustic photon map lookup size : integer
    • Number of photons that should be fetched in photon map queries (Default: 120)

  • Work unit granularity : integer
    • Granularity of photon tracing work units for the purpose of parallelization (in # of shot particles) (Default: 0, i.e. decide automatically)

  • Hide Emitters : boolean
    • Hide directly visible emitters? See page 149 for details. (Default: no, i.e. false)


  • 最終更新:2014-05-20 15:30:09

このWIKIを編集するにはパスワード入力が必要です

認証パスワード