# OptiX **URL:** https://forums.developer.nvidia.com/c/gaming-and-visualization-technologies/visualization/optix/167.md [Latest](https://forums.developer.nvidia.com/latest.md) · [Categories](https://forums.developer.nvidia.com/categories.md) · [Tags](https://forums.developer.nvidia.com/tags.md) --- ## [OptiX 9.1 Release](https://forums.developer.nvidia.com/t/optix-9-1-release/354119)
**Author:** [@dhart](https://forums.developer.nvidia.com/u/dhart)\ **Replies:** 1\ **Last updated:** [January 13, 2026, 11:12pm UTC](https://forums.developer.nvidia.com/t/optix-9-1-release/354119 "2026-01-13T23:12:00Z")
OptiX 9.1 has been released! NOTE: support for OptiX 6 based applications has been removed from the driver as of R590. You can continue to use OptiX 6 by using the R580 driver or earlier. Here are the main highlights f… --- ## [OptiX sample for real-time animated subdivision surfaces + DLSS-RR](https://forums.developer.nvidia.com/t/optix-sample-for-real-time-animated-subdivision-surfaces-dlss-rr/331986)
**Author:** [@dlacewell](https://forums.developer.nvidia.com/u/dlacewell)\ **Replies:** 10\ **Last updated:** [April 23, 2026, 6:13pm UTC](https://forums.developer.nvidia.com/t/optix-sample-for-real-time-animated-subdivision-surfaces-dlss-rr/331986 "2026-04-23T18:13:06Z")
We want to direct your attention to a new code sample on GitHub for real-time animated subdivision surfaces using OptiX and CUDA: There is also a corresponding tech blog article. This sample uses the Cluster API avai… --- ## [Solving Self-Intersection Artifacts in OptiX](https://forums.developer.nvidia.com/t/solving-self-intersection-artifacts-in-optix/267805)
**Author:** [@dhart](https://forums.developer.nvidia.com/u/dhart)\ **Replies:** 0\ **Last updated:** [September 27, 2023, 8:00pm UTC](https://forums.developer.nvidia.com/t/solving-self-intersection-artifacts-in-optix/267805 "2023-09-27T20:00:53Z")
Recently one of our team members published a solution and code examples for how to avoid self-intersection artifacts in OptiX as well as DirectX and Vulkan. Despite having “DirectX” in the title, this works just as well … --- ## [OptiX advanced samples on github](https://forums.developer.nvidia.com/t/optix-advanced-samples-on-github/48410)
**Author:** [@dlacewell](https://forums.developer.nvidia.com/u/dlacewell)\ **Replies:** 20\ **Last updated:** [April 28, 2025, 4:08pm UTC](https://forums.developer.nvidia.com/t/optix-advanced-samples-on-github/48410 "2025-04-28T16:08:30Z")
In case you’re missing some of the more advanced samples like “glass” that were removed from the SDK in OptiX 4.0, we’ve put a handful of them on github: OptiX Advanced Samples Along the way we switched from GLUT to … --- ## [Move cluster operation?](https://forums.developer.nvidia.com/t/move-cluster-operation/382661)
**Author:** [@shocker.0x15](https://forums.developer.nvidia.com/u/shocker.0x15)\ **Replies:** 8\ **Last updated:** [October 6, 2026, 3:59am UTC](https://forums.developer.nvidia.com/t/move-cluster-operation/382661 "2026-10-06T03:59:26Z")
Hello, I’m now extending my demo program for CLAS/Cluster GAS in my wrapper library so that it can reuse CLASes built in the last frame if they are still drawn instead of rebuilding them. However, when building Cluster… --- ## [Understanding Register Allocation in Optix ray-gen kernel](https://forums.developer.nvidia.com/t/understanding-register-allocation-in-optix-ray-gen-kernel/385039)
**Author:** [@meetbanthia](https://forums.developer.nvidia.com/u/meetbanthia)\ **Replies:** 1\ **Last updated:** [October 5, 2026, 10:47am UTC](https://forums.developer.nvidia.com/t/understanding-register-allocation-in-optix-ray-gen-kernel/385039 "2026-10-05T10:47:26Z")
Hi all, I’m trying to understand the effect of register allocation in OptiX ray-gen code. My ray-gen code is something like this: ray-gen(){ while(some condition){ optixTrace(); // uses 32 max registers in pa… --- ## [Driver 616.64: Some OptiX-IR kernel crashes in Debug](https://forums.developer.nvidia.com/t/driver-616-64-some-optix-ir-kernel-crashes-in-debug/382461)
**Author:** [@shocker.0x15](https://forums.developer.nvidia.com/u/shocker.0x15)\ **Replies:** 1\ **Last updated:** [September 7, 2026, 10:27am UTC](https://forums.developer.nvidia.com/t/driver-616-64-some-optix-ir-kernel-crashes-in-debug/382461 "2026-09-07T10:27:39Z")
Hello, Recently, I have updated the driver to 616.64 and noticed a program in my OptiX wrapper library crashes in Debug build. As always :), I suspected OptiX-IR and gave ptx try instead, then the crash disappeared. I… --- ## [Running OptiX on WSL (2026 version)](https://forums.developer.nvidia.com/t/running-optix-on-wsl-2026-version/382414)
**Author:** [@dhart](https://forums.developer.nvidia.com/u/dhart)\ **Replies:** 0\ **Last updated:** [September 4, 2026, 8:03pm UTC](https://forums.developer.nvidia.com/t/running-optix-on-wsl-2026-version/382414 "2026-09-04T20:03:40Z")
Hi all, While we’re still working (slowly) on official OptiX support in the WSL drivers, Kyle has refreshed the instructions for manually getting OptiX to work in WSL. We hope this helps people, but please remember thes… --- ## [SER crashes, part 2](https://forums.developer.nvidia.com/t/ser-crashes-part-2/380905)
**Author:** [@michael.nikelsky](https://forums.developer.nvidia.com/u/michael.nikelsky)\ **Replies:** 6\ **Last updated:** [September 1, 2026, 9:30am UTC](https://forums.developer.nvidia.com/t/ser-crashes-part-2/380905 "2026-09-01T09:30:17Z")
Sadly it looks like I have to revive this topic. We are in the situation where SER works most of the time for me on two Blackwell Max-Q GPUs but for my colleague on two RTX 6000 Ada it crashes quite often. So I did a re… --- ## [OptiX™ 6.X Download](https://forums.developer.nvidia.com/t/optix-6-x-download/356773)
**Author:** [@reebot](https://forums.developer.nvidia.com/u/reebot)\ **Replies:** 4\ **Last updated:** [August 26, 2026, 8:57am UTC](https://forums.developer.nvidia.com/t/optix-6-x-download/356773 "2026-08-26T08:57:14Z")
Hi, I would like to download this old version of Optix but it start at 7.X on the download page. Could you provide a link to it ? Thanks. --- ## [Siggraph 2026 OptiX talk & slides - RTX Rendering Day](https://forums.developer.nvidia.com/t/siggraph-2026-optix-talk-slides-rtx-rendering-day/380743)
**Author:** [@dhart](https://forums.developer.nvidia.com/u/dhart)\ **Replies:** 0\ **Last updated:** [August 20, 2026, 11:05pm UTC](https://forums.developer.nvidia.com/t/siggraph-2026-optix-talk-slides-rtx-rendering-day/380743 "2026-08-20T23:05:58Z")
Recently at Siggraph 2026, we held the RTX Rendering Day where we discussed some of the upcoming features planning for OptiX 9.2 and beyond, as well as how and why to integrate DLSS into an OptiX application. Here’s a li… --- ## [Legacy SDK version 4.1.1](https://forums.developer.nvidia.com/t/legacy-sdk-version-4-1-1/380218)
**Author:** [@egsewel](https://forums.developer.nvidia.com/u/egsewel)\ **Replies:** 6\ **Last updated:** [August 20, 2026, 10:37pm UTC](https://forums.developer.nvidia.com/t/legacy-sdk-version-4-1-1/380218 "2026-08-20T22:37:53Z")
Hello - I’m trying to compile some legacy software that has a dependency on OptiX version 4.1.1 (pre 7.0 release that still bundles the runtime with the SDK). Is there any way to obtain legacy versions of the SDK for c… --- ## [OptiX Debugging Techniques](https://forums.developer.nvidia.com/t/optix-debugging-techniques/378831)
**Author:** [@dhart](https://forums.developer.nvidia.com/u/dhart)\ **Replies:** 1\ **Last updated:** [August 20, 2026, 8:24pm UTC](https://forums.developer.nvidia.com/t/optix-debugging-techniques/378831 "2026-08-20T20:24:13Z")
Hi all, Richard recently published a developer blog post that highlights the debugging facilities in the OptiX Toolkit (OTK). In the blog post, he walks through how to use OTK for logging and debugging. We will have mor… --- ## [How to debug IAS refit crash?](https://forums.developer.nvidia.com/t/how-to-debug-ias-refit-crash/380695)
**Author:** [@iaomw](https://forums.developer.nvidia.com/u/iaomw)\ **Replies:** 1\ **Last updated:** [August 20, 2026, 5:15pm UTC](https://forums.developer.nvidia.com/t/how-to-debug-ias-refit-crash/380695 "2026-08-20T17:15:21Z")
After enabling SER, the driver seems checking more strictly. I got crashes while refitting nested IAS with new matries per frame. However it doesn’t crash at all if I enable OPTIX\_DEVICE\_CONTEXT\_VALIDATION\_MODE\_ALL. I wa… --- ## [Practical way to use SER on Principled shader](https://forums.developer.nvidia.com/t/practical-way-to-use-ser-on-principled-shader/379995)
**Author:** [@iaomw](https://forums.developer.nvidia.com/u/iaomw)\ **Replies:** 1\ **Last updated:** [August 13, 2026, 5:17pm UTC](https://forums.developer.nvidia.com/t/practical-way-to-use-ser-on-principled-shader/379995 "2026-08-13T17:17:54Z")
Principled shader is an older thing with many branches, they are driven by random value and many parameters. Parameters are derived from node graph at runtime, they could be different per shading point even on the same o… --- ## [Optix 9.1 illegal memory access](https://forums.developer.nvidia.com/t/optix-9-1-illegal-memory-access/377664)
**Author:** [@s37jmaie](https://forums.developer.nvidia.com/u/s37jmaie)\ **Replies:** 7\ **Last updated:** [July 22, 2026, 8:48pm UTC](https://forums.developer.nvidia.com/t/optix-9-1-illegal-memory-access/377664 "2026-07-22T20:48:44Z")
Hi, I’m new to raytracing and I am building a simple renderer for a university project. I created a single OptixModule with one Pipeline and was able to trace Radiance and Shadow Rays. However now i wanted to create a … --- ## [Ray precision in IAS](https://forums.developer.nvidia.com/t/ray-precision-in-ias/373969)
**Author:** [@whix](https://forums.developer.nvidia.com/u/whix)\ **Replies:** 7\ **Last updated:** [July 19, 2026, 5:51am UTC](https://forums.developer.nvidia.com/t/ray-precision-in-ias/373969 "2026-07-19T05:51:27Z")
Hi, I am working with a very large mesh that contains both large coordinate values and extremely small triangles. To reduce vertex precision issues caused by the large coordinates, I partitioned the mesh into multiple c… --- ## [Question about the construction time of multiple GASs when building IAS](https://forums.developer.nvidia.com/t/question-about-the-construction-time-of-multiple-gass-when-building-ias/376425)
**Author:** [@whix](https://forums.developer.nvidia.com/u/whix)\ **Replies:** 4\ **Last updated:** [July 12, 2026, 12:42am UTC](https://forums.developer.nvidia.com/t/question-about-the-construction-time-of-multiple-gass-when-building-ias/376425 "2026-07-12T00:42:31Z")
Hi, I am splitting my triangle mesh into multiple chunks and building an IAS over the resulting GASes. However, I observed that building many small GASes is significantly slower than building a single large GAS. In my … --- ## [OptiX 9.1 false-hit / 7.7 all-miss with CAD SubDMesh triangles — working standalone test](https://forums.developer.nvidia.com/t/optix-9-1-false-hit-7-7-all-miss-with-cad-subdmesh-triangles-working-standalone-test/374871)
**Author:** [@arbiter314](https://forums.developer.nvidia.com/u/arbiter314)\ **Replies:** 3\ **Last updated:** [June 29, 2026, 1:50pm UTC](https://forums.developer.nvidia.com/t/optix-9-1-false-hit-7-7-all-miss-with-cad-subdmesh-triangles-working-standalone-test/374871 "2026-06-29T13:50:03Z")
I’m building a GPU-accelerated sunlight analysis engine. My setup: RTX 4090, CUDA 13.3, Driver 610.62, Win11, VS2022, OptiX SDK 7.7 & 9.1 tested. Problem: GPU occlusion rays exhibit opposite incorrect behavior in differ… --- ## [Optix 9.0 optixHitObjectGetTriangleBarycentrics](https://forums.developer.nvidia.com/t/optix-9-0-optixhitobjectgettrianglebarycentrics/349300)
**Author:** [@m.breitzke](https://forums.developer.nvidia.com/u/m.breitzke)\ **Replies:** 5\ **Last updated:** [June 15, 2026, 1:18am UTC](https://forums.developer.nvidia.com/t/optix-9-0-optixhitobjectgettrianglebarycentrics/349300 "2026-06-15T01:18:06Z")
Hi, I’m using optixTraverse to get some hit info. In some (rare) cases I need the barycentrics of a triangle hit. I’m doing something like: uint hitKind = optixHitObjectGetHitKind ( ); if ( optixGetPrimitiveType ( hit… --- ## [Questions about watertight ray-triangle intersection](https://forums.developer.nvidia.com/t/questions-about-watertight-ray-triangle-intersection/371982)
**Author:** [@whix](https://forums.developer.nvidia.com/u/whix)\ **Replies:** 5\ **Last updated:** [June 5, 2026, 8:53am UTC](https://forums.developer.nvidia.com/t/questions-about-watertight-ray-triangle-intersection/371982 "2026-06-05T08:53:48Z")
Hi, I am testing watertight ray–triangle intersection and have the following three cases: A ray hits an edge of a single triangle. A ray hits an edge shared by two triangles. A ray hits an edge shared by three … --- ## [PTX case infinite waiting, OptixIR works flawless](https://forums.developer.nvidia.com/t/ptx-case-infinite-waiting-optixir-works-flawless/371499)
**Author:** [@iaomw](https://forums.developer.nvidia.com/u/iaomw)\ **Replies:** 10\ **Last updated:** [May 29, 2026, 3:23pm UTC](https://forums.developer.nvidia.com/t/ptx-case-infinite-waiting-optixir-works-flawless/371499 "2026-05-29T15:23:01Z")
Last year we changed to support both ptx and optix-ir, because nvrtc or nsight always complaining ptx does support some debug features…blablabla. Both worked flawless by then. However I found it’s broken this week, I ne… --- ## [Optix on WSL (Windows Subsystem for Linux)](https://forums.developer.nvidia.com/t/optix-on-wsl-windows-subsystem-for-linux/140297)
**Author:** [@til](https://forums.developer.nvidia.com/u/til)\ **Replies:** 34\ **Last updated:** [May 19, 2026, 9:28am UTC](https://forums.developer.nvidia.com/t/optix-on-wsl-windows-subsystem-for-linux/140297 "2026-05-19T09:28:42Z")
With the experimental support for CUDA on WSL out I was wondering if Optix is also able to run on WSL. I tried a sample project earlier but was not able to get it to run. Although I am still not sure if I did it right ;) … --- ## [Any suggestions for detecting intersections within a customized region defined per ray?](https://forums.developer.nvidia.com/t/any-suggestions-for-detecting-intersections-within-a-customized-region-defined-per-ray/367410)
**Author:** [@whix](https://forums.developer.nvidia.com/u/whix)\ **Replies:** 5\ **Last updated:** [May 13, 2026, 9:58am UTC](https://forums.developer.nvidia.com/t/any-suggestions-for-detecting-intersections-within-a-customized-region-defined-per-ray/367410 "2026-05-13T09:58:25Z")
Hi, I am exploring general applications of RT cores. Given a large set of points in space, I aim to determine whether two points can be connected. The criterion is that no other points lie within the intersection region… --- ## [OptiX CMake build setup with modern CUDA](https://forums.developer.nvidia.com/t/optix-cmake-build-setup-with-modern-cuda/369433)
**Author:** [@papaboo](https://forums.developer.nvidia.com/u/papaboo)\ **Replies:** 3\ **Last updated:** [May 12, 2026, 2:23pm UTC](https://forums.developer.nvidia.com/t/optix-cmake-build-setup-with-modern-cuda/369433 "2026-05-12T14:23:43Z")
Hey I’ve been upgrading my OptiX renderer in my multi-renderer engine from 6.5 to 7.0+. Incrementally as OptiX 9.1 requires a driver that deprecates my old 6.5 based renderer. :D As part of the upgrade I was hoping I c… --- ## [Divergence and warps behaviour in OptiX ray tracing](https://forums.developer.nvidia.com/t/divergence-and-warps-behaviour-in-optix-ray-tracing/367662)
**Author:** [@meetbanthia](https://forums.developer.nvidia.com/u/meetbanthia)\ **Replies:** 2\ **Last updated:** [April 29, 2026, 2:20am UTC](https://forums.developer.nvidia.com/t/divergence-and-warps-behaviour-in-optix-ray-tracing/367662 "2026-04-29T02:20:55Z")
Hi all, I had few confusions and I wanted to clarify those. In OptiX, is each ray is associated with one thread? I’m trying to understand divergence issue in traversal and I recently came across this paper https://res… --- ## [surf2Dwrite\ from OptiX raygen causes device fault on Ada (SM 8.9), while surf2Dwrite\ with identical bytes works](https://forums.developer.nvidia.com/t/surf2dwrite-uchar4-from-optix-raygen-causes-device-fault-on-ada-sm-8-9-while-surf2dwrite-uint32-t-with-identical-bytes-works/367431)
**Author:** [@schrodinger\_s\_cat](https://forums.developer.nvidia.com/u/schrodinger_s_cat)\ **Replies:** 1\ **Last updated:** [April 22, 2026, 9:49am UTC](https://forums.developer.nvidia.com/t/surf2dwrite-uchar4-from-optix-raygen-causes-device-fault-on-ada-sm-8-9-while-surf2dwrite-uint32-t-with-identical-bytes-works/367431 "2026-04-22T09:49:02Z")
Hi OptiX team, I’m hitting a reproducible device fault when calling surf2Dwrite\(v, surface, x\*4, y) from an OptiX raygen program. The exact same write, emitted as surf2Dwrite\(packed, surface, x\*4, y) w… --- ## [Trimesh.ray equivalent in Optix](https://forums.developer.nvidia.com/t/trimesh-ray-equivalent-in-optix/366868)
**Author:** [@medamimessaoud](https://forums.developer.nvidia.com/u/medamimessaoud)\ **Replies:** 1\ **Last updated:** [April 17, 2026, 9:32am UTC](https://forums.developer.nvidia.com/t/trimesh-ray-equivalent-in-optix/366868 "2026-04-17T09:32:18Z")
Hello, I’m new starting to wok with Optix. I’m trying to reproduce the same output of as mesh\_rot = trimesh.Trimesh(vertices=origins\_rot, faces=mesh\_for\_shadow.faces,process=False) -- \>shadowed = mesh\_rot.ray.inter… --- ## [Problem with linking libraries at Optix 9.0](https://forums.developer.nvidia.com/t/problem-with-linking-libraries-at-optix-9-0/366706)
**Author:** [@medamimessaoud](https://forums.developer.nvidia.com/u/medamimessaoud)\ **Replies:** 2\ **Last updated:** [April 15, 2026, 2:22pm UTC](https://forums.developer.nvidia.com/t/problem-with-linking-libraries-at-optix-9-0/366706 "2026-04-15T14:22:19Z")
Hello, I’am trying to build a hello world project with optix 9.0. However I am finding a difficulty to use. (conan-env) aminated@aminated-HP-ZBook-Fury-17-3-inch-G8:~/Downloads/doc-optix/hello$ ./build.sh ======== Inp… --- ## ["Unsupported ABI version"](https://forums.developer.nvidia.com/t/unsupported-abi-version/366134)
**Author:** [@Mr\_F](https://forums.developer.nvidia.com/u/Mr_F)\ **Replies:** 5\ **Last updated:** [April 10, 2026, 2:35pm UTC](https://forums.developer.nvidia.com/t/unsupported-abi-version/366134 "2026-04-10T14:35:47Z")
I have a certain user of my OptiX9 program (Bakery GPU lightmapper) using driver 595.79 on an RTX 3080. On their machine initializing OptiX results in “Unsupported ABI version”. Tried to google that, but couldn’t find an… [Next page](https://forums.developer.nvidia.com/c/gaming-and-visualization-technologies/visualization/optix/167.md?page=1)