SLR:

IBL image: sIBL Archive

SLRはモンテカルロレイトレーシングに基づいたレンダラーです。
SLR is a renderer based on Monte Carlo ray tracing.

SLRは次の要素から構成されています。
SLR consists of the following components.

• libSLR - レンダリングコア / rendering core
• libSLRSceneGraph - シーン管理・読み込み機能 / scene managing & loading
• HostProgram

特徴 / Features

• Full Spectral Rendering (Monte Carlo Spectral Sampling)
  (For RGB resources, RGB->Spectrum conversion is performed using Meng-Simon's method [Meng2015].)
• RGB Rendering
• BSDFs
  • Ideal Diffuse (Lambert) BRDF
  • Ideal Specular BRDF/BSDF
  • Oren-Nayer BRDF [Oren1994]
  • Improved Ward-Dür BRDF [Moroder2010]
  • Ashikhmin-Shirley BRDF [Ashikhmin2000]
  • GGX Microfacet BRDF/BSDF [Walter2007] with visible normal sampling [Heitz2017]
  • Disney principled BRDF/BSDF (TODO) [Burley2012, Burley2015]
  • Mixed BSDF
  • Layered BSDF (TODO)
• Volume Rendering [Pauly1999, Raab2008, Novák2014]
  • Participating Media
    • Homogeneous Media
    • Heterogeneous Media
      • Trilinear-interpolated Grid
      • Procedurally-generated Clouds (TODO)
      • Free Path Sampling is accelerated by Super-voxels [Szirmay-Kalos2011]
    • Media enclosed by surfaces
  • Phase Functions
    • Isotropic
    • Henyey-Greenstein
    • Schlick
• Texture Types
  • Constant
  • Image
  • Procedural
    • Checkerboard (color & normal & float)
    • Cell Noise [Worley1996] like Voronoi diagram (color & normal & float)
    • Improved Perlin Noise [Perlin2002] (float & normal)
• Bump Mapping (Normal Map)
• Light Source Types
  • Area (Polygonal) Light
  • Infinitely Distant Image Based Environmental Light
  • Infinitely Distant Directional Light (TODO)
  • Analytic Sky Dome & Sun [Hosek2012]
• Light Distributions
  • Diffuse
  • Ideal Directional
• Camera Types
  • Perspective Camera with Depth of Field (thin-lens model)
  • Environment (Equirectangular) Camera
• Motion Blur
  • Camera Motion Blur
  • Object Motion Blur
  • Deformation Blur (TODO)
• Geometry Instancing
• Acceleration Structure Types
  • Standard BVH (median, mid-point, binned SAH)
  • Split BVH [Stich2009]
  • QBVH [Dammertz2008] constructed by collapsing SBVH
• Light Transport Algorithms
  • Path Tracing [Kajiya1986] with MIS (+ volumetric variant)
  • Bidirectional Path Tracing [Veach1994, 1997] (+ volumetric variant)
  • Adaptive MCMC Progressive Photon Mapping [Hachisuka2011]
    (has been dropped from current SLR implementation.)
• Correct handling of non-symmetric scattering due to shading normals [Veach1996, 1997]
• SLR Custom Language (C/Python-like syntax) for flexible scene description

動作環境 / Confirmed Environment

現状以下の環境で動作を確認しています。
I've confirmed that the program runs correctly on the following environment.

• OS X 10.12.5 & Xcode 8.3.2 (Apple LLVM-Clang 8.1.0)
• Windows 8.1 & Visual Studio 2015 Update 3 (MSVC 14.0, character-encoding conversion required)
• MacBook Pro Retina Late 2013

動作させるにあたっては以下のライブラリが必要です。
It requires the following libraries.

• OpenEXR 2.2
• libpng 1.6
• assimp 3.2

注意 / Note

モデルデータやテクスチャーを読み込むシーンファイルがありますが、それらアセットはリポジトリには含まれていません。

There are some scene files loading model data and textures, but those assets are NOT included in this repository.

参考文献 / References

[Ashikhmin2000] "An Anisotropic Phong BRDF Model"
[Bridson2007] "Curl-Noise for Procedural Fluid Flow"
[Burley2012] "Physically-Based Shading at Disney"
[Burley2015] "Extending the Disney BRDF to a BSDF with Integrated Subsurface Scattering"
[Dammertz2008] "Shallow Bounding Volume Hierarchies for Fast SIMD Ray Tracing of Incoherent Rays"
[Hachisuka2011] "Robust Adaptive Photon Tracing Using Photon Path Visibility"
[Heitz2017] "A Simpler and Exact Sampling Routine for the GGX Distribution of Visible Normals"
[Hosek2012] "An Analytic Model for Full Spectral Sky-Dome Radiance"
[Kajiya1986] "THE RENDERING EQUATION"
[Meng2015] "Physically Meaningful Rendering using Tristimulus Colours"
[Moroder2010] "A New Ward BRDF Model with Bounded Albedo"
[Novák2014] "Residual ratio tracking for estimating attenuation in participating media"
[Oren1994] "Generalization of Lambert’s Reflectance Model"
[Pauly1999] "Robust Monte Carlo Methods for Photorealistic Rendering of Volumetric Effects"
[Perlin2002] "Improving Noise"
[Raab2008] "Unbiased Global Illumination with Participating Media"
[Stich2009] "Spatial Splits in Bounding Volume Hierarchies"
[Szirmay-Kalos2011] "Free Path Sampling in High Resolution Inhomogeneous Participating Media"
[Veach1994] "Bidirectional Estimators for Light Transport"
[Veach1996] "Non-symmetric Scattering in Light Transport Algorithms"
[Veach1997] "ROBUST MONTE CARLO METHODS FOR LIGHT TRANSPORT SIMULATION"
[Walter2007] "Microfacet Models for Refraction through Rough Surfaces"
[Worley1996] "A Cellular Texture Basis Function"

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