Graphics Programming weekly - Issue 35 — April 22, 2018


2018 Vulkan Developer Day in Montréal

  • April 30th, Vulkan Developer Day in Montreal, hosted by Ubisoft


Recolouring assets with lazy unwrapping!

  • UVs map into a gradient texture
  • to change the colors the UVs are adjusted to point to other sections in gradient texture


The Machinery Shader System (part 2)

  • overview of the shader authoring format
  • shader input parameters are defined without thinking about how they are bound
  • passing data between shader stages is abstracted
    • giving the system flexibility to pack as required


Dissecting the NVIDIA Volta GPU Architecture via Microbenchmarking

  • microarchitectural details of the NVIDIA Volta architecture
  • registers are divided into two 64 bit banks
    • reduction of bank conflicts with register remapping can improve performance by 15%
  • shorter latency for shared memory atomics


Benefits of Image Based Lighting on Mobile

  • MatCap texture contains lighting information for all camera space normals
  • needs to be recalculated when camera direction changes


Post-processing effects on optimization mobile gaming

  • uses a texture based and camera facing quad approach instead of a post-processing bloom
  • lighting for terrain rendered into a low-res light map, sampled per-fragment
  • terrain is rendered at 720p, up-scaled to 1080p


Prefix Sums and Summed Area Tables

  • algorithm to sum regions from arrays or grids in constant time
  • need larger storage format, increase depends on largest range that needs to be summed
  • compatible with bilinear filtering for sub-pixel values


Unity Graphics Questionnaire

  • unity graphics team is looking to gather feedback to improve the roadmap


Daily Pathtracer 10: Update C#&GPU

  • performance numbers for all implementations with latest changes

Daily Pathtracer 11: Buffer-Oriented

  • current approach recursively processes a single ray until it terminates
  • new approach calculates each step for all rays in seperate passes
  • memory read seems to be limiting factor, shows a few optimizations for that


First steps when implementing FP16

  • available with AMD vega architecture
  • pack two FP16 into FP32 register
    • reduce ALU instructions count, reduce VGPR usage
  • how to detect FP16 code generation in FXC disassembly and GCN ISA output
  • discussion of pitfalls and common use-cases
  • how to deal with FP16 constants


Rainy SurfaceShader in UE4 Part 2

  • combination of ripples and streaking effect
  • blending between the two effects based on surface orientation
  • this post covers the implementation of the streaking effect


BC7 encoding using weighted YCbCr colorspace metrics

  • many BC7 encoders compress all channels equally
  • for color textures, errors in red and blue are less noticeable
  • YCbCr color space allows better compression by reducing the number of bits used for chroma


ispc_texcomp BC7 issues

  • discusses issue with the ispc implementation
  • compression has quality problems with grayscale textures


Monte Carlo Methods for Volumetric Light Transport Simulation

  • survey of methods utilizing Monte Carlo for light transport in participating media


Readings (shaders, maths, 3D)

  • list of resources for beginners aimed at shader toy like graphics programming


fx-gltf

  • A C++14/C++17 header-only library for simple, efficient, and robust serialization/deserialization of glTF 2.0

intel metrics discovery

  • library that allows access to GPU performance data on intel GPUs