Graphics Programming weekly - Issue 234 - May 8, 2022

Derivatives in compute shader

  • the article discusses how to calculate UV derivatives in compute-shaders
  • presents issues that will occur at the geometry edges and how to resolve them

Let’s Stop Calling it GGX

  • the blog post raises the point that GGX was introduced in a 1975 paper by Trowbridge and Reitz
  • discusses why we as a community should prefer to use the original term

How to build a BVH – part 5: TLAS & BLAS

  • the article presents how to extend the BVH structure to allow multiple objects in the same structure (TLAS)
  • explains the necessary knowledge of matrix (inverse) transformations

High Performance Graphics 2022 - Student Competition

  • the High-Performance Graphics conference is running a student contest
  • students are asked to implement the highest quality path-tracer within a performance limit

Various analytic expressions for collimated light scattered in fog (participating media)

  • the article presents the underlying mathematical modeling commonly used to represent volumetric effects (such as the earth’s atmosphere)
  • presents different approaches and derivations to model different effects

Efficiency-aware multiple importance sampling for bidirectional rendering algorithms

  • the paper presents a method to adapt the set of sampling techniques in multi importance sampling to an input scene automatically
  • the aim is to remove the need for manual tweaking of distributions
  • based on a scheme for estimating the second moments of different sample allocation strategies

Sampling the hemisphere

  • the blog post explains the derivations of importance sampling schemes for multiple functions
  • covers uniform, Cosine-weighted, Power cosine-weighted, Microfacet-BRDF, Blinn-Phong, as well as Beckmann derivations

ReSTIR El-Cheapo

  • the article presents the idea of using ReSTIR for a checkerboard style pattern for shadow ray generation
  • only every other pixel would sample new; others would reuse the reservoir of nearby pixels

Increasing wave coherence with ray binning

  • the article presents the implementation of a ray-binning technique
  • the technique aims to improve performance by processing rays that are likely to hit similar objects together

Generalized Resampled Importance Sampling (GRIS)

  • the paper introduces a generalized approach to resampled importance sampling for correlated samples with unknown PDFs
  • presents the results in an interactive ReSTIR path tracer

[video] Sprite Batching In OpenGL // Uniform Buffer Objects

  • the video shows how to pack sprites into a 2D texture atlas to reduce the number of draw calls required
  • presents how to set up the vertex data and shader stages to unpack the data
  • it additionally explains uniform buffer objects and presents the effects on performance

Thanks to Stephen Hill for support of this series.

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