# \#cpp **URL:** https://forum.aousd.org/tag/cpp/5.md [Latest](https://forum.aousd.org/latest.md) · [Categories](https://forum.aousd.org/categories.md) · [Tags](https://forum.aousd.org/tags.md) --- ## [Export Hair Guides to DCCs](https://forum.aousd.org/t/export-hair-guides-to-dccs/3050)
**Author:** [@madoodia](https://forum.aousd.org/u/madoodia)\ **Replies:** 0\ **Last updated:** [September 23, 2026, 6:35pm UTC](https://forum.aousd.org/t/export-hair-guides-to-dccs/3050 "2026-09-23T18:35:26Z")
Hello all I hope everything goes well I like to share my current under development standalone Grooming Software, and latest update that is exporting USDA file from it and open in other DCCs like usdView, maya, houdini … --- ## [HdStorm + Vulkan + Qt QML](https://forum.aousd.org/t/hdstorm-vulkan-qt-qml/3041)
**Author:** [@andreagenor](https://forum.aousd.org/u/andreagenor)\ **Replies:** 5\ **Last updated:** [September 15, 2026, 3:04am UTC](https://forum.aousd.org/t/hdstorm-vulkan-qt-qml/3041 "2026-09-15T03:04:29Z")
Hi, We’re building a USD/Hydra viewer that integrates HdStorm with Qt QML/QtQuick via Vulkan. Our current architecture: Device ownership: HgiVulkan creates the unique VkDevice/VkInstance/VkPhysicalDevice AOV handoff: … --- ## [Animation slow initial playthrough](https://forum.aousd.org/t/animation-slow-initial-playthrough/3034)
**Author:** [@Iciar](https://forum.aousd.org/u/Iciar)\ **Replies:** 4\ **Last updated:** [September 1, 2026, 12:47am UTC](https://forum.aousd.org/t/animation-slow-initial-playthrough/3034 "2026-09-01T00:47:58Z")
Hello! I have been working on ways to load and handle USD data in Maya and I have noticed that when I load a USD file that contains some animation the first playthrough always runs slow (lower fps) and then the rest of … --- ## [How to dynamically cast \`TfAnyWeakPtr\`?](https://forum.aousd.org/t/how-to-dynamically-cast-tfanyweakptr/3025)
**Author:** [@maddy-adams](https://forum.aousd.org/u/maddy-adams)\ **Replies:** 1\ **Last updated:** [August 28, 2026, 6:28pm UTC](https://forum.aousd.org/t/how-to-dynamically-cast-tfanyweakptr/3025 "2026-08-28T18:28:41Z")
Given a TfAnyWeakPtr, is there a way to dynamically cast it to a typed TfWeakPtr\? pxr/base/tf/anyWeakPtr.h declares templated method TfAnyWeakPtrDynamicCast, but I can’t see a definition for it anywhere in the OpenUSD… --- ## [Introducing Roji: An End-to-End OpenUSD Workflow for Scene Assembly, Look Development, Lighting and Rendering](https://forum.aousd.org/t/introducing-roji-an-end-to-end-openusd-workflow-for-scene-assembly-look-development-lighting-and-rendering/3028)
**Author:** [@RABIA](https://forum.aousd.org/u/RABIA)\ **Replies:** 0\ **Last updated:** [August 27, 2026, 4:16pm UTC](https://forum.aousd.org/t/introducing-roji-an-end-to-end-openusd-workflow-for-scene-assembly-look-development-lighting-and-rendering/3028 "2026-08-27T16:16:06Z")
Hi everyone, I’m Rabia Rahou, founder of Roji Research, I’m developing Roji, an end-to-end OpenUSD environment that brings scene assembly, look development, lighting, interactive review and rendering into one connected… --- ## [Why SdfSchemaBase and SdfSchema?](https://forum.aousd.org/t/why-sdfschemabase-and-sdfschema/3023)
**Author:** [@maddy-adams](https://forum.aousd.org/u/maddy-adams)\ **Replies:** 1\ **Last updated:** [August 25, 2026, 12:57am UTC](https://forum.aousd.org/t/why-sdfschemabase-and-sdfschema/3023 "2026-08-25T00:57:28Z")
Why are SdfSchemaBase and SdfSchema different classes? Is this just a historical artifact, or is there a reason they can’t be merged/treated as the same? Are there other classes in OpenUSD that derive from SdfSchemaBas… --- ## [Rendering multiple realtime scenes in different viewports with Hydra/HdStorm](https://forum.aousd.org/t/rendering-multiple-realtime-scenes-in-different-viewports-with-hydra-hdstorm/2895)
**Author:** [@Grimmigbeisser](https://forum.aousd.org/u/Grimmigbeisser)\ **Replies:** 2\ **Last updated:** [June 8, 2026, 1:03pm UTC](https://forum.aousd.org/t/rendering-multiple-realtime-scenes-in-different-viewports-with-hydra-hdstorm/2895 "2026-06-08T13:03:56Z")
I have a scenario, where I have a lot of scenes in small thumbnail viewports and a couple of big render viewports with more complex scenes. I am using hydra directly via a setup of custom rendertasks and scene indices, … --- ## [NVIDIA Omniverse Custom Extension: From Scan to Digital Twin](https://forum.aousd.org/t/nvidia-omniverse-custom-extension-from-scan-to-digital-twin/2927)
**Author:** [@Finger](https://forum.aousd.org/u/Finger)\ **Replies:** 1\ **Last updated:** [June 2, 2026, 3:51pm UTC](https://forum.aousd.org/t/nvidia-omniverse-custom-extension-from-scan-to-digital-twin/2927 "2026-06-02T15:51:32Z")
NVIDIA Omniverse is showcasing a demo application that utilizes CurvSurf FindSurface technology. Here are the key features: Users can upload point clouds stored on their computers directly into the Omniverse App. FindS… --- ## [Unexpected calls to custom ArResolver \_CreateDefaultContextForAsset for uriSchemes list longer than 1](https://forum.aousd.org/t/unexpected-calls-to-custom-arresolver-createdefaultcontextforasset-for-urischemes-list-longer-than-1/2881)
**Author:** [@JStroudBrahma](https://forum.aousd.org/u/JStroudBrahma)\ **Replies:** 2\ **Last updated:** [April 14, 2026, 10:19am UTC](https://forum.aousd.org/t/unexpected-calls-to-custom-arresolver-createdefaultcontextforasset-for-urischemes-list-longer-than-1/2881 "2026-04-14T10:19:37Z")
Hi, I have a query around the calling of \_CreateDefaultContextForAsset by the resolver.cpp implementation and how it is mapping scheme to resolver. I’ve recently noticed some unexpected behaviour from our in-house Usd … --- ## [How to use the Hydra 2.0 API to parse geomSubset types](https://forum.aousd.org/t/how-to-use-the-hydra-2-0-api-to-parse-geomsubset-types/2870)
**Author:** [@zitai](https://forum.aousd.org/u/zitai)\ **Replies:** 0\ **Last updated:** [March 3, 2026, 2:13am UTC](https://forum.aousd.org/t/how-to-use-the-hydra-2-0-api-to-parse-geomsubset-types/2870 "2026-03-03T02:13:54Z")
At present, I am using the Hydra 1.0 API for parsing .usd files. Recently, I learned that upgrading to Hydra 2.0 API has brought many powerful features (thank you to all developers for your contributions). I want to migr… --- ## [Path length limitation when creating a USD layer](https://forum.aousd.org/t/path-length-limitation-when-creating-a-usd-layer/2853)
**Author:** [@GreatWhite](https://forum.aousd.org/u/GreatWhite)\ **Replies:** 3\ **Last updated:** [February 11, 2026, 7:19am UTC](https://forum.aousd.org/t/path-length-limitation-when-creating-a-usd-layer/2853 "2026-02-11T07:19:27Z")
Hi experts, When I use pxr::SdfLayer::CreateNew() to create a new USD layer, the API fails to create the file if the path length is greater than 260. Is there any recommended practice to address this issue? Thanks --- ## [How to affect the rendered image by OpenExec](https://forum.aousd.org/t/how-to-affect-the-rendered-image-by-openexec/2838)
**Author:** [@rkat](https://forum.aousd.org/u/rkat)\ **Replies:** 6\ **Last updated:** [February 6, 2026, 6:35pm UTC](https://forum.aousd.org/t/how-to-affect-the-rendered-image-by-openexec/2838 "2026-02-06T18:35:39Z")
Hi, I am currently experimenting with a simple constraint implementation using OpenExec. My goal is to create a MyConstraintAPI that can be applied to xformable prims. This API has a relationship with a target xformable… --- ## [OpenUSD C++ api documentation](https://forum.aousd.org/t/openusd-c-api-documentation/2797)
**Author:** [@Trylz](https://forum.aousd.org/u/Trylz)\ **Replies:** 0\ **Last updated:** [December 18, 2025, 2:26am UTC](https://forum.aousd.org/t/openusd-c-api-documentation/2797 "2025-12-18T02:26:19Z")
I want to add USD support to my C++ software using OpenUSD but I don’t find any examples. I basically need to import USD meshes and materials in my application. I found some tutorials located at extras\\usd\\tutorials but … --- ## [Overriding nested references issue / behaviour](https://forum.aousd.org/t/overriding-nested-references-issue-behaviour/2767)
**Author:** [@Joachim\_Ante](https://forum.aousd.org/u/Joachim_Ante)\ **Replies:** 13\ **Last updated:** [December 1, 2025, 12:53am UTC](https://forum.aousd.org/t/overriding-nested-references-issue-behaviour/2767 "2025-12-01T00:53:59Z")
Hi, I ran into an issue in overriding references in USD. I made a small example of this using the “Parking Lot” language to make it understandable. I have a car with wheels in a parking lot. The car is made out of ref… --- ## [Rendering Selection Outline in Hydra w/ Storm?](https://forum.aousd.org/t/rendering-selection-outline-in-hydra-w-storm/2772)
**Author:** [@joao\_dgg](https://forum.aousd.org/u/joao_dgg)\ **Replies:** 3\ **Last updated:** [November 24, 2025, 7:57am UTC](https://forum.aousd.org/t/rendering-selection-outline-in-hydra-w-storm/2772 "2025-11-24T07:57:23Z")
Are we able to render selection outlines with Hydra and, specifically, Storm? From the HdTaskController API, it seems like that should be possible with SetSelectionEnableOutline, but no matter what I do I can only see t… --- ## [UsdGeomXformCommonAPI throws Coding Errors due to Attribute Precision](https://forum.aousd.org/t/usdgeomxformcommonapi-throws-coding-errors-due-to-attribute-precision/2766)
**Author:** [@valmiq](https://forum.aousd.org/u/valmiq)\ **Replies:** 2\ **Last updated:** [November 17, 2025, 8:37am UTC](https://forum.aousd.org/t/usdgeomxformcommonapi-throws-coding-errors-due-to-attribute-precision/2766 "2025-11-17T08:37:06Z")
I realized the UsdGeomXformCommonAPI throws Coding Errors if there is a composed reference that has different float/double precision in its transform operators. For example, if the USD scale was defined as double, since … --- ## [How to readback AOVs from glslfx shader?](https://forum.aousd.org/t/how-to-readback-aovs-from-glslfx-shader/2653)
**Author:** [@Grimmigbeisser](https://forum.aousd.org/u/Grimmigbeisser)\ **Replies:** 3\ **Last updated:** [October 1, 2025, 10:53am UTC](https://forum.aousd.org/t/how-to-readback-aovs-from-glslfx-shader/2653 "2025-10-01T10:53:57Z")
Hi, i am working on a custom outline glslfx shader for hdstorm. My idea was to use the primid and instanceid AOVs for edge detection. I wrote a custom HdxTask, which uses an HdSt\_ImageShaderRenderPass. To supply the AOV… --- ## [Custom Memory Management for OpenUSD on Native Windows x64 C++](https://forum.aousd.org/t/custom-memory-management-for-openusd-on-native-windows-x64-c/2594)
**Author:** [@PaulSkibitzke](https://forum.aousd.org/u/PaulSkibitzke)\ **Replies:** 2\ **Last updated:** [September 2, 2025, 6:52pm UTC](https://forum.aousd.org/t/custom-memory-management-for-openusd-on-native-windows-x64-c/2594 "2025-09-02T18:52:51Z")
All our native libraries (Windows x64) must use our own API for all memory management. Any static lib not doing so is detected and will throw an exception. My current workaround, wrapping all direct calls to OpenUSD in… --- ## [Support different material binding purposes based on current active display purposes](https://forum.aousd.org/t/support-different-material-binding-purposes-based-on-current-active-display-purposes/2633)
**Author:** [@Mithridates](https://forum.aousd.org/u/Mithridates)\ **Replies:** 0\ **Last updated:** [August 5, 2025, 2:07pm UTC](https://forum.aousd.org/t/support-different-material-binding-purposes-based-on-current-active-display-purposes/2633 "2025-08-05T14:07:13Z")
Problem Description In the current OpenUSD implementation, a render delegate specifies its supported material via the GetMaterialBindingPurpose() function, which means only materials with a matching purpose are instantia… --- ## [Purpose of UsdPhysicsRigidBodyDesc structure](https://forum.aousd.org/t/purpose-of-usdphysicsrigidbodydesc-structure/2612)
**Author:** [@untxen](https://forum.aousd.org/u/untxen)\ **Replies:** 1\ **Last updated:** [July 29, 2025, 1:43pm UTC](https://forum.aousd.org/t/purpose-of-usdphysicsrigidbodydesc-structure/2612 "2025-07-29T13:43:03Z")
Hi all! while working on with Physics I noticed the structure UsdPhysicsRigidBodyDesc. I am trying to understand the reason for its existance as I have not seen anything that consumes the struct directly. Does it play … --- ## [Can't get absolute asset path from relative asset path](https://forum.aousd.org/t/cant-get-absolute-asset-path-from-relative-asset-path/2604)
**Author:** [@justinwang](https://forum.aousd.org/u/justinwang)\ **Replies:** 2\ **Last updated:** [July 28, 2025, 1:52am UTC](https://forum.aousd.org/t/cant-get-absolute-asset-path-from-relative-asset-path/2604 "2025-07-28T01:52:33Z")
Hi experts, For attached usd files reference.zip (6.5 KB), API SdfLayer::ComputeAbsolutePath(const std::string& assetPath) doesn’t work for the following asset path in red. Is there any other API works? My c++ code: p… --- ## [Can USD C++ toolkit load a model with external references like this?](https://forum.aousd.org/t/can-usd-c-toolkit-load-a-model-with-external-references-like-this/2586)
**Author:** [@justinwang](https://forum.aousd.org/u/justinwang)\ **Replies:** 3\ **Last updated:** [July 18, 2025, 8:30am UTC](https://forum.aousd.org/t/can-usd-c-toolkit-load-a-model-with-external-references-like-this/2586 "2025-07-18T08:30:44Z")
Hi USD experts, I am meeting an issue to need your support. For attached sublayers.usda, it references another two external “TwoBoxes.usda”, “mesh.usda” in “sub” folders. Now, I try to change folder name on the disk - “s… --- ## [OpenAsset with custom ArResolver](https://forum.aousd.org/t/openasset-with-custom-arresolver/2539)
**Author:** [@SteveGhee](https://forum.aousd.org/u/SteveGhee)\ **Replies:** 3\ **Last updated:** [June 23, 2025, 7:57pm UTC](https://forum.aousd.org/t/openasset-with-custom-arresolver/2539 "2025-06-23T19:57:11Z")
Hi. I have implemented a small custom Asset Resolver plugin which successfully registers and ‘resolves’ when usdview opens a usd file containing my URI asset reference e.g. @steve:someID@. \_Resolve() is called with the … --- ## [HdMeshUtil::ComputeTriangleIndices and the UsdGeomSubset indices attribute](https://forum.aousd.org/t/hdmeshutil-computetriangleindices-and-the-usdgeomsubset-indices-attribute/2504)
**Author:** [@omnnai](https://forum.aousd.org/u/omnnai)\ **Replies:** 0\ **Last updated:** [June 6, 2025, 4:30am UTC](https://forum.aousd.org/t/hdmeshutil-computetriangleindices-and-the-usdgeomsubset-indices-attribute/2504 "2025-06-06T04:30:19Z")
I am using Hydra for a typical rasterizer with a Vulkan backend. I rely on the HdMeshUtil::ComputeTriangleIndices to produce a single index buffer that can be used for reading from various vertex streams. Some meshes s… --- ## [Controlling the visibility and transform of a whole usd stage](https://forum.aousd.org/t/controlling-the-visibility-and-transform-of-a-whole-usd-stage/2474)
**Author:** [@dlanier](https://forum.aousd.org/u/dlanier)\ **Replies:** 0\ **Last updated:** [May 23, 2025, 12:51pm UTC](https://forum.aousd.org/t/controlling-the-visibility-and-transform-of-a-whole-usd-stage/2474 "2025-05-23T12:51:20Z")
Hi, In order to control the visibility and transform of all prims from a usd stage in Hydra 2.0, we use a UsdImagingRootOverridesSceneIndex and we add a HdFlatteningSceneIndex (only for visibility and xform) to apply th… --- ## [Opening a USD stage and rendering in a separate thread](https://forum.aousd.org/t/opening-a-usd-stage-and-rendering-in-a-separate-thread/2456)
**Author:** [@mmarkd8](https://forum.aousd.org/u/mmarkd8)\ **Replies:** 1\ **Last updated:** [May 17, 2025, 5:32am UTC](https://forum.aousd.org/t/opening-a-usd-stage-and-rendering-in-a-separate-thread/2456 "2025-05-17T05:32:06Z")
I have a C++ physical simulation app which opens the USD stage to read physics from it and start the simulation. Now I’d like a simple debug visualization but I’m really concerned that this might impact my simulation req… --- ## [How to setup a zbias and alpha threshold for rendering decals](https://forum.aousd.org/t/how-to-setup-a-zbias-and-alpha-threshold-for-rendering-decals/2449)
**Author:** [@Grimmigbeisser](https://forum.aousd.org/u/Grimmigbeisser)\ **Replies:** 2\ **Last updated:** [May 15, 2025, 6:58am UTC](https://forum.aousd.org/t/how-to-setup-a-zbias-and-alpha-threshold-for-rendering-decals/2449 "2025-05-15T06:58:24Z")
Hi, i am setting up an HdxRenderTask with the following code: auto decoRenderTaskId = GetControllerId().AppendChild(TfToken(“renderTask\_decorations”)); GetRenderIndex()-\>InsertTask(&delegate, decoRenderTaskId); HdxRen… --- ## [How can I create materials programmatically code with hydra?](https://forum.aousd.org/t/how-can-i-create-materials-programmatically-code-with-hydra/2405)
**Author:** [@orhun](https://forum.aousd.org/u/orhun)\ **Replies:** 4\ **Last updated:** [May 6, 2025, 2:07am UTC](https://forum.aousd.org/t/how-can-i-create-materials-programmatically-code-with-hydra/2405 "2025-05-06T02:07:49Z")
Hi, How can I create materials programmatically with Hydra 2? I have been looking into HdMaterialNetwork2, and HdMaterialNode2, etc, but I am not sure whether I am on the correct path. Are there any resources, you cou… --- ## [How do I get CMake to generate the Xcode file described in this tutorial?](https://forum.aousd.org/t/how-do-i-get-cmake-to-generate-the-xcode-file-described-in-this-tutorial/2421)
**Author:** [@dub1988](https://forum.aousd.org/u/dub1988)\ **Replies:** 0\ **Last updated:** [May 1, 2025, 11:38pm UTC](https://forum.aousd.org/t/how-do-i-get-cmake-to-generate-the-xcode-file-described-in-this-tutorial/2421 "2025-05-01T23:38:53Z")
In the Creating A 3D Application With Hydra Rendering tutorial on the Apple Developer website, on the last step where I execute this command: cmake -S ~/Users/macuser/CreatingA3DApplicationWithHydraRendering/ -B ~/Users/… --- ## [Will USD support C++23 in the future?](https://forum.aousd.org/t/will-usd-support-c-23-in-the-future/2319)
**Author:** [@BigRayLee](https://forum.aousd.org/u/BigRayLee)\ **Replies:** 1\ **Last updated:** [March 19, 2025, 2:35pm UTC](https://forum.aousd.org/t/will-usd-support-c-23-in-the-future/2319 "2025-03-19T14:35:53Z")
Will USD support C++23 in the future? [Next page](https://forum.aousd.org/tag/cpp/5.md?match_all_tags=true&page=1&tags%5B%5D=cpp)