@ScieCode

Graphics Engineer

sciecode.com/sheen
Joined May 2019
  • Tweets216
  • Following132
  • Followers499
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Guilherme Avila retweeted
Arseny Kapoulkine@zeuxcg4 May 2025
New blog post! "Load store conflicts", in which we look at some performance sensitive code that has surprisingly dramatic performance swings based on the compiler and the microarchitecture used. RTs appreciated! zeux.io/2025/05/03/load-stor…

Load-store conflicts

meshoptimizer implements several geometry compression algorithms that are designed to take advantage of redundancies common in mesh data and decompress quickly - targeting many gigabytes per second...

zeux.io
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Guilherme Avila retweeted
Arseny Kapoulkine@zeuxcg25 Oct 2024
GH stars / retweets welcome as usual ;) GitHub release link: github.com/zeux/meshoptimize…

Release v0.22 · zeux/meshoptimizer

This release contains many improvements to the meshoptimizer library and some gltfpack enhancements! Notably, meshopt_simplifyWithAttributes has seen significant improvements to attribute handling,...

github.com
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I see Stubbe's octahedral decode opt in almost every usage I come across. But I've never seen it used for encoding. The same symmetry applies here! and its ~50% faster. Especially important for octahedral-encoded textures, as it's required for every sample! please RT.
Rune Stubbe@Stubbesaurus5 Dec 2017
After playing around with symmetries for a bit, this seems like a cute and slightly faster way to decode octahedral normals than what seems to have become the standard approach. No outer conditional and reusing 1.0-abs(..) terms from n.z.
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follow-up optimization xitter.cf/ScieCode/status/181108…
Guilherme Avila@ScieCode10 Jul 2024
Found another potential optimization, breaking up instruction dependency, and allowing better pipeline while quarter-rate rcp runs. Got mixed results here, either no net gain or ~5% gain. Probably depends on the compiler, but should use this formulation eitherway.
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Found another potential optimization, breaking up instruction dependency, and allowing better pipeline while quarter-rate rcp runs. Got mixed results here, either no net gain or ~5% gain. Probably depends on the compiler, but should use this formulation eitherway.
Guilherme Avila@ScieCode10 Jul 2024
I see Stubbe's octahedral decode opt in almost every usage I come across. But I've never seen it used for encoding. The same symmetry applies here! and its ~50% faster. Especially important for octahedral-encoded textures, as it's required for every sample! please RT.
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Worth noting, snippet expects unit normals & returns uv in [-1,1] range (remap to [0,1] afterwards if the API expects that range)
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Guilherme Avila retweeted
Arseny Kapoulkine@zeuxcg25 Jun 2024
meshoptimizer v0.21 is out! This release has many improvements related to meshlets: a new function to optimize meshlets for HW efficiency, extra features for meshopt_simplify* to make Nanite style processing easier to implement and faster, and more! RTs and ⭐️ appreciated :)
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Example of full padded octahedral-encoded mipchain. Pre-convolved with GGX roughness lobes.
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Octahedral-encoded indirect specular map, with added border so it allows bilinear filtering, pre-convolved mips & trivially tiled within texture atlas. shadertoy.com/view/43G3Dd
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different spectral band
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plasma tornado. I love the sun.
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Currently, there isn't a physically correct way to filter + blend a .png ImageBitmap uploaded to WebGPU. Either filtering occurs in sRGB, or premultiplied-alpha does. As such, if you want photometric correct .png textures you need decode it manually. rawcdn.githack.com/sciecode/…
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more replies
The point is - this is not something new. The information about having to filter, blend & premultiply-alpha in linear-space in order to properly handle cutouts & correct radiance/luminance data has been out there for at least 25 years.
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So why, when I load a .png to a HTMLImageElement, does it filter + blend & premultiply-alpha in sRGB? This sort of thing frustrates more than I can put into words.
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