Publications and Presentations
Parallel Axis Split Tasks for Bounding Volume Construction with OpenMP
GRAPP - Short Paper (Porto, Portugal, February 26-28, 2025)
Proceedings of the 20th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications - (Volume 1)
Proceedings of the 20th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications - (Volume 1)
Many algorithms in computer graphics make use of acceleration structures such as
Bounding Volume Hierarchies (BVHs) to speed up performance critical tasks, such
as collision detection or ray-tracing. However, while the typical algorithms for
constructing BVHs are relatively simple, actually implementing them for
performance critical systems is still challenging. Further, to construct them as
quickly as possible, it is also desirable to parallelize the process. To that
end, parallelization APIs such as OpenMP® can be leveraged to greatly simplify
this matter. However, BVH construction is not a trivially parallelizable
problem. Thus, in this paper we propose a method of using OpenMP® tasking to
further parallelize the spatial splitting algorithm and thus improve
construction performance. We evaluate the proposed way and compare it with other
ways of using OpenMP®, finding that some of these work well to improve the
construction time by between 3 and 5 times on an 8-core machine with a minimal
amount of work and negligible quality reduction of the final BVH.
@conference{grapp25, author = {Gustaf Waldemarson and Michael Doggett}, title = {Parallel Axis Split Tasks for Bounding Volume Construction with OpenMP}, booktitle = {Proceedings of the 20th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications - GRAPP}, year = {2025}, pages = {347-354}, publisher = {SciTePress}, organization = {INSTICC}, doi = {10.5220/0013317100003912}, isbn = {978-989-758-728-3}, issn = {2184-4321}, }
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- PBRT: Create your own Importers and Exporters
BCON24 - Blender Conference 2024 - Presentation (Felix Meritis, Amsterdam, October 23-25, 2024)
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}, }
- Succinct Opacity Micromaps
High-Performance Graphics - Paper (Denver, Colorado, July 26-28 2024)
Proceedings of the ACM on Computer Graphics and Interactive Techniques, Volume 7, Issue 3
Proceedings of the ACM on Computer Graphics and Interactive Techniques, Volume 7, Issue 3
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} }
- Handling Custom Data in glTF Files with Exporter/Importer Plugins
BCON23 - Blender Conference 2023 - Presentation (Felix Meritis, Amsterdam, October 26-28, 2023)
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}, }
- Photon Mapping Superluminal Particles
Eurographics - Short Paper (Norrköping, Sweden, May 25-29, 2020)
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} }
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