Clustered Geometry, Partitioned TLAS, Indirect Acceleration Structure Builds
Comments on “Clustered Geometry, Partitioned TLAS, Indirect Acceleration Structure Builds”
Claim-checked. Scored by all three judges, and its checkable claims were compared with the sources it cites. How far stories are checked
Microsoft released a preview of DirectX Raytracing Clustered Geometry and Partitioned TLAS, with GPU-driven build and update calls, in Agility SDK 1.722 and Shader Model 6.10. Clusters of up to 256 triangles are assembled into BLAS, and PTLAS rebuilds only changed scene regions. In Microsoft's own AMD RX 9070 sample, frame rate rose from 1.2 to 79 FPS, though scratch memory grew and the test covers one configuration. Support currently spans RTX, Radeon RX 9000 and Intel Arc B-series, with Qualcomm expected in 2027.
Why it ranked
No. 6 of 110 with a score of 0.70. The panel rated it highest on new information (0.96) and technical depth (0.95), lowest on audience breadth (0.57). Placed No. 6, No. 9 by score alone: the placement terms moved other stories past it.
- AI judgeJudge 2claude-haiku-5-5
- Official DirectX API preview with detailed technical specification, samples and vendor support; substantive and practical for graphics and engine builders, though niche in audience.
- AI judgeJudge 3gpt-5.6-luna
- A substantive DXR preview with detailed APIs, GPU-driven build mechanics, prerequisites, samples, benchmarks, and vendor support. It is highly actionable for graphics engineers, though audience breadth is narrower than general software development.
Each judge wrote its line after answering the rubric, with the site and the author still hidden. Every answer behind this is in the table under Score.
Score
0.70total under rubric v2.3
- Significance0.69
- Reader interest0.77
- Audience breadth0.57
- Practical relevance0.78
- Substantiated0.90
- Technical depth0.95
- New information0.96
- Counts against: Promotional0.13
- Counts against: Overclaim0.24
Each judge’s answer per question (0–1), their mean and spread, and what the question adds to the score (weight × mean).
| Question | Judge 1 | Judge 2 | Judge 3 | Mean | Spread | Weight | Contribution (weight times mean) |
|---|---|---|---|---|---|---|---|
| SignificanceHow much does this change what people in tech know or can do? | 0.64 | 0.60 | 0.82 | 0.69 | 0.22 | +0.24 | +0.165 |
| Reader interestWould a well-informed senior engineer or tech founder want to read this today, and likely pass it on? | 0.61 | 0.80 | 0.90 | 0.77 | 0.29 | +0.26 | +0.200 |
| Audience breadthHow many people who build technology does it concern? | 0.54 | 0.55 | 0.62 | 0.57 | 0.08 | +0.13 | +0.074 |
| Practical relevanceHow useful is it to someone who builds software or tech products? | 0.79 | 0.70 | 0.86 | 0.78 | 0.16 | +0.22 | +0.172 |
| SubstantiatedHow well is it backed? Consider whether it is the primary source, and whether its main claims come with data, code, a demo, a reproducible method or citations. | 0.96 | 0.80 | 0.93 | 0.90 | 0.16 | +0.05 | +0.045 |
| Technical depthHow technically substantive is it? | 0.99 | 0.90 | 0.96 | 0.95 | 0.09 | +0.05 | +0.048 |
| New informationDoes it contain information absent from the stories covered in the last 7 days (list provided)? | 0.93 | 0.95 | 0.99 | 0.96 | 0.06 | +0.05 | +0.048 |
| PromotionalIs it mainly marketing with little substance (a press release, ad or sponsored post with no real information)? A launch post that carries real news is not promotional. | 0.10 | 0.20 | 0.08 | 0.13 | 0.12 | −0.19 | −0.024 |
| OverclaimDo the headline or conclusions claim more than the body supports? | 0.33 | 0.20 | 0.18 | 0.24 | 0.15 | −0.11 | −0.026 |
| Sum of contributions | +0.702 | ||||||
| Claim-check penalty | 0.000 | ||||||
| Total, as published | 0.702 | ||||||
Spread is the highest minus the lowest judge answer. marks a spread above 0.40: the judges disagree, and the story is marked contested.
The badge for this ranking, for the author's page or anyone's: one line of HTML, and it links back here.
<a href="https://rubric.hrih.si/editions/2026-10-29/6/"><img src="https://rubric.hrih.si/badge/2026-10-29/6.svg" alt="Ranked #6 on Rubric, 29 Oct 2026" width="238" height="28"></a>Claim check
Claim check: 2 matches source · 6 no source given. Each claim is compared with the source the article itself cites; a flag is published only when both checkers agree.
No source givenFirst, only or fastest
The clustered geometry and Partitioned TLAS preview is the most significant update to DirectX Raytracing since its debut in 2018.
The article gives no link or citation for it.
The article says “For DXR this is the most significant update since its debut in 2018”
The source says No source to compare with.
Matches sourceNumber
A Cluster Level Acceleration Structure (CLAS) contains an indexed mesh of up to 256 triangles and 256 vertices.
The cited source says the same thing.
The article says “A Cluster Level Acceleration Structure (CLAS) contains an indexed mesh of up to 256 triangles and 256 vertices”
The source says “The limit is 256 triangles and 256 unique vertex indices, one cluster per CLAS”
Source cited by the article: github.com/microsoft/DirectX-Specs/blob/master/d3d/Raytracing2.md
Matches sourceGeneralization
Gears of War: E-Day is an early example of a title adopting clustered geometry through NVIDIA's vendor-specific RTX Mega Geometry API.
The cited source says the same thing.
The article says “is an early example of a title adopting clustered geometry through NVIDIA’s vendor-specific API, RTX Mega Geometry”
The source says “These debut today in Gears of War: E-Day, and will be adopted by Microsoft’s DirectX Raytracing 2.0 standard (DXR 2.0”
Source cited by the article: nvidia.com/en-us/geforce/news/gears-of-war-e-day-dlss-4-5-ray-tracing-rtx-mega-geometry
No source givenBenchmark result
On an AMD RX 9070 in the clustered geometry sample, frame rate rose from 1.2 FPS with traditional BLAS rebuild to 79 FPS with clustered geometry, about 66x higher.
The article gives no link or citation for it.
The article says “Frame rate 1.2 FPS 79 FPS ~66x higher”
The source says No source to compare with.
No source givenBenchmark result
In the same sample, per-frame GPU acceleration structure build time fell from 788 ms to 3.11 ms, about 254x less.
The article gives no link or citation for it.
The article says “Per-frame GPU AS preparation/build 788 ms 3.11 ms ~254x less time”
The source says No source to compare with.
No source givenBenchmark result
In the same sample, total acceleration structure memory including TLAS fell from 7,519 MiB to 774 MiB, 89.7% less.
The article gives no link or citation for it.
The article says “Total AS memory, including TLAS 7,519 MiB 774 MiB 89.7% less”
The source says No source to compare with.
No source givenBenchmark result
In the domino sample, a full TLAS rebuild each frame takes 2.88 ms while PTLAS with 4702 localized writes takes 0.79 ms.
The article gives no link or citation for it.
The article says “TLAS needs a full rebuild each frame and takes 2.88ms, while PTLAS with localized writes (4702 in this case) only takes 0.79ms”
The source says No source to compare with.
No source givenGeneralization
Clustered Geometry and PTLAS do not require new hardware capabilities beyond existing raytracing support.
The article gives no link or citation for it.
The article says “These features don’t require new hardware capabilities beyond existing raytracing support”
The source says No source to compare with.
Also covered by
No other coverage was clustered with this story.
Elsewhere
Elsewhere: HN 1 pts, not on front page
Recorded for context only, checked 29 Oct 2026, 05:47 UTC. It played no part in the ranking.