# Encountered a CUDA error when add two Transform node to a Group node **URL:** \ **Category:** OptiX\ **Created:** [December 10, 2015, 6:14am UTC](https://forums.developer.nvidia.com/t/encountered-a-cuda-error-when-add-two-transform-node-to-a-group-node/40596 "2015-12-10T06:14:37Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![superpdm](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@superpdm](https://forums.developer.nvidia.com/u/superpdm)\ **Post date:** [December 10, 2015, 6:14am UTC](https://forums.developer.nvidia.com/t/encountered-a-cuda-error-when-add-two-transform-node-to-a-group-node/40596/1 "2015-12-10T06:14:37Z")
```auto //create first Transform node GeometryGroup object_group = LoadDataMesh(furniture->GetMesh()); Transform optix_mesh = m_Context->createTransform(); optix_mesh->setMatrix(true, (float*)&furniture->GetMatrix(),0); optix_mesh->setChild(object_group); //create second transform node similarly GeometryGroup object_group1 = LoadDataMesh(furniture->GetMesh()); Transform optix_mesh1 = m_Context->createTransform(); optix_mesh1->setMatrix(true, (float*)&furniture->GetMatrix(), 0); optix_mesh1->setChild(object_group1); //add Transform to Group, which is also the top object of ray tracing m_RootGroup->addChild(optix_mesh); m_RootGroup->addChild(optix_mesh1); ``` when add optix\_mesh and optix\_mesh1 to the Group node, then call context-\>launch(0,0,0), it fails with “Unknown error (Details: Function "\_rtContextLaunch2D" caught exception: Encountered a CUDA error: Kernel launch returned (719): Launch failed, [6619200])” However, when I just add one mesh (no matter optix\_mesh or optix\_mesh1) to Group node, it works normally and i get the correct image. And more, if optix\_mesh and optix\_mesh1 share the same GeometryGroup child, it also works. But when they do not share the same GeoemtryGroup , the error above still appears. Please help me… System information: Windows 7 Utimate 64 SP1, Nvidia Titan X,driver version 358.91, otpix 3.8.0, cuda v7.0.27. I’m using 32bit application. ---
**Author:** ![Smejkal](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@Smejkal](https://forums.developer.nvidia.com/u/Smejkal)\ **Post date:** [December 10, 2015, 7:16am UTC](https://forums.developer.nvidia.com/t/encountered-a-cuda-error-when-add-two-transform-node-to-a-group-node/40596/2 "2015-12-10T07:16:09Z")
Hi, be sure, that you have set acceleration structure for m\_RootGroup correctly. ---
**Author:** ![superpdm](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@superpdm](https://forums.developer.nvidia.com/u/superpdm)\ **Post date:** [December 10, 2015, 7:45am UTC](https://forums.developer.nvidia.com/t/encountered-a-cuda-error-when-add-two-transform-node-to-a-group-node/40596/3 "2015-12-10T07:45:11Z")
> [@](#): > > Hi, > be sure, that you have set acceleration structure for m\_RootGroup correctly. Yes, this is how I set up the m\_RootGroup ```auto m_RootGroup = m_Context->createGroup(); m_RootGroup->setAcceleration(m_Context->createAcceleration("Trbvh", "Bvh")); m_Context["_TOP_OBJECT"]->set(m_RootGroup); ``` ---
**Author:** ![droettger](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/droettger/32/14043_2.png) [@droettger](https://forums.developer.nvidia.com/u/droettger)\ **Post date:** [December 10, 2015, 8:41am UTC](https://forums.developer.nvidia.com/t/encountered-a-cuda-error-when-add-two-transform-node-to-a-group-node/40596/4 "2015-12-10T08:41:36Z")
When reporting issues please always list at least the following information: OS version, installed GPU(s), display driver version, OptiX version, CUDA Toolkit version used. Application bitness should be 64-bit, there won’t be support for 32-bit anymore. CUDA error 719 is a CUDA\_ERROR\_LAUNCH\_FAILED. You’ll find these enums in cuda.h of the CUDA toolkit. Unfortunately that’s just the CUDA generic error for “something went wrong” and doesn’t help much to isolate what exactly didn’t work. If the error happens with a dummy launch which validates the OptiX state, compiles the kernel, and builds the acceleration structures, this could be a problem with the acceleration structure (AS) build. In such cases try to isolate this by using other AS builders, for example Bvh instead of Trbvh. If you aren’t using the newest available OptiX 3.8.0 version, try that. If OptiX 3.8.0 doesn’t help, but Bvh worked, try again with the next upcoming OptiX release which should be out very soon. If Bvh or that newest OptiX version still fails you might have a different problem. Then an OptiX API Capture (OAC) trace would be needed to see what API calls you’re really doing. Please see this thread for instructions how produce an OAC trace: [url][https://devtalk.nvidia.com/default/topic/803116/?comment=4436953[/url]](https://devtalk.nvidia.com/default/topic/803116/?comment=4436953%5B/url%5D) ---
**Author:** ![superpdm](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@superpdm](https://forums.developer.nvidia.com/u/superpdm)\ **Post date:** [December 10, 2015, 12:04pm UTC](https://forums.developer.nvidia.com/t/encountered-a-cuda-error-when-add-two-transform-node-to-a-group-node/40596/5 "2015-12-10T12:04:28Z")
It turns out that my LoadDataMesh has loaded mtl file wrongly. Although it doesn’t explain why it always fails at the second Transform node, the problem does disappear now.Thanks Detlef and Smejkal for help ---
**Author:** ![TomNVIDIA](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/tomnvidia/32/14181_2.png) [@TomNVIDIA](https://forums.developer.nvidia.com/u/TomNVIDIA)\ **Post date:** [June 14, 2022, 9:11pm UTC](https://forums.developer.nvidia.com/t/encountered-a-cuda-error-when-add-two-transform-node-to-a-group-node/40596/6 "2022-06-14T21:11:25Z")