Publications and Presentations

Succinct Opacity Micromaps
Gustaf Waldemarson, Michael Doggett

High-Performance Graphics - Paper (Denver, Colorado, July 26-28 2024)
Proceedings of the ACM on Computer Graphics and Interactive Techniques, Volume 7, Issue 3

Succinct Opacity Micromaps
Sponza Ecosys San-Miguel Landscape

Alpha masked geometry such as foliage has long been one of the trickier things to render efficiently, both for rasterization based approaches and for hardware accelerated ray-tracing. Recently, a new type of primitive was introduced to the Vulkan® and DirectX® ray-tracing APIs that promises to alleviate this issue: Opacity Micromaps, a structure that uses a bit of extra memory as hints to the pipeline when it should actually call the AnyHit-shader. In this paper, we extend this primitive with a novel compression method that uses the concept of succinct 4-way trees to reduce the memory footprint by up to 110 times, including an algorithm for looking up micromap values directly from this compressed form. Further, we perform a comprehensive analysis of the generated micromaps to demonstrate their performance in terms of both memory footprint and frame render time compared to a number of similar structures. Finally, we highlight some aspects of the extension that developers and artists should be aware of to make the most out of it. 

@article{10.1145/3675385,
  author       = {Waldemarson, Gustaf and Doggett, Michael},
  title        = {Succinct Opacity Micromaps},
  year         = {2024},
  issue_date   = {August 2024},
  publisher    = {Association for Computing Machinery},
  address      = {New York, NY, USA},
  volume       = {7},
  number       = {3},
  url          = {https://doi.org/10.1145/3675385},
  doi          = {10.1145/3675385},
  abstract     = {Alpha masked geometry such as foliage has long been one of the
                  trickier things to render efficiently, both for rasterization
                  based approaches and for hardware accelerated
                  ray-tracing. Recently, a new type of primitive was introduced
                  to the Vulkan® and DirectX® ray-tracing APIs that promises to
                  alleviate this issue: Opacity Micromaps, a structure that uses
                  a bit of extra memory as hints to the pipeline when it should
                  actually call the AnyHit-shader. In this paper, we extend this
                  primitive with a novel compression method that uses the
                  concept of succinct 4-way trees to reduce the memory footprint
                  by up to 110 times, including an algorithm for looking up
                  micromap values directly from this compressed form. Further,
                  we perform a comprehensive analysis of the generated micromaps
                  to demonstrate their performance in terms of both memory
                  footprint and frame render time compared to a number of
                  similar structures. Finally, we highlight some aspects of the
                  extension that developers and artists should be aware of to
                  make the most out of it.},
  journal      = {Proc. ACM Comput. Graph. Interact. Tech.},
  month        = {aug},
  articleno    = {45},
  numpages     = {18},
  keywords     = {Compression, Opacity Micromaps, Ray Tracing}
}

Gustaf Waldemarson

BCON24 - Blender Conference 2024 - Presentation (Felix Meritis, Amsterdam, October 23-25, 2024)
PBRT: Create your own Importers and Exporters

Blender is arguably one of the best tools for performing a wide variety graphics work, and while Eevee and Cycles are great renderers, sometimes it is desirable to create a more specialized rendering engine for some particular task. However, getting data into these engines can sometimes be challenging. Thus, in this talk I will present some of the work I have done to connect Blender with the well known research renderer: PBRT, allowing Blender to export scenes in the native PBRT format or import existing PBRT scenes into Blender for further editing. Furthermore, this work should be easily adaptable such that you can use it you create your own importer, exporter or even renderer if you want to!

@online{waldemarsonBCON24,
  title        = {PBRT: Create your own Importers and Exporters},
  year         = {2024},
  organization = {The Blender Foundation, Youtube},
  author       = {Gustaf Waldemarson},
  url          = {https://youtu.be/BEbscsBRIx0},
}

Gustaf Waldemarson

BCON23 - Blender Conference 2023 - Presentation (Felix Meritis, Amsterdam, October 26-28, 2023)
Custom Data in glTF files with Blender

Blender is arguably one of the best tools for developing a wide variety of assets, and glTF is often a good export format for real-time graphics applications given how much of it supports and how extensible it is. However, handling glTF files with application specific content is still somewhat tricky in Blender, often requiring pretty deep knowledge of both the glTF format and the Blender scripting API.

During this presentation, the basic developer view of the glTF Blender IO add-on is presented with a focus on using it to create custom importer and exporters plugins to extract or embed almost arbitrary data from or into glTF files.

@online{waldemarsonBCON23,
  title        = {Handling Custom Data in glTF Files with Exporter/Importer Plugins},
  year         = {2023},
  organization = {The Blender Foundation, Youtube},
  author       = {Gustaf Waldemarson},
  url          = {https://youtu.be/4fBGM8qc21M?t=1783},
}

Gustaf Waldemarson, Michael Doggett

Eurographics - Short Papers (Norrköping, Sweden, May 25-29, 2020)
Single charged particle inside a Cornell box Many charged particles with cylinders of varying refractive index. Rendering of our Reed reactor model.

One type of light source that remains largely unexplored in the field of light transport rendering is the light generated by superluminal particles, a phenomenon more commonly known as Cherenkov radiation. By re-purposing the Frank-Tamm equation for rendering, the energy output of these particles can be estimated and consequently mapped to photons, making it possible to visualize the brilliant blue light characteristic of the effect. In this paper we extend a stochastic progressive photon mapper and simulate the emission of superluminal particles from a source object close to a medium with a high index of refraction. In practice, the source is treated as a new kind of light source, allowing us to efficiently reuse existing photon mapping methods. 

@inproceedings {s.20201004,
  booktitle    = {Eurographics 2020 - Short Papers},
  editor       = {Wilkie, Alexander and Banterle, Francesco},
  title        = {{Photon Mapping Superluminal Particles}},
  author       = {Waldemarson, Gustaf and Doggett, Michael},
  year         = {2020},
  publisher    = {The Eurographics Association},
  ISSN         = {1017-4656},
  ISBN         = {978-3-03868-101-4},
  DOI          = {10.2312/egs.20201004}
}