C Specification

The xrGetSceneMeshBuffersMSFT function retrieves the scene mesh vertex buffer and index buffer for the given scene mesh buffer identifier.

Note

Applications may use the scene mesh buffer identifier as a key to cache the vertices and indices of a mesh for reuse within an XrSceneMSFT or across multiple XrSceneMSFT for the same XrSession.

Applications can avoid unnecessarily calling xrGetSceneMeshBuffersMSFT for a scene component if XrSceneComponentMSFT::updateTime is equal to the XrSceneComponentMSFT::updateTime value in the previous XrSceneMSFT. A scene component is uniquely identified by XrUuidMSFT.

This function follows the two-call idiom for filling multiple buffers in a struct.

The xrGetSceneMeshBuffersMSFT function is defined as:

XrResult xrGetSceneMeshBuffersMSFT(
    XrSceneMSFT                                 scene,
    const XrSceneMeshBuffersGetInfoMSFT*        getInfo,
    XrSceneMeshBuffersMSFT*                     buffers);

Parameters

Parameter Descriptions

Description

Applications can request the vertex buffer of the mesh by including XrSceneMeshVertexBufferMSFT in the XrSceneMeshBuffersMSFT::next chain. Runtimes must support requesting a 32-bit index buffer and may support requesting a 16-bit index buffer. Applications can request a 32-bit index buffer by including XrSceneMeshIndicesUint32MSFT in the XrSceneMeshBuffersMSFT::next chain. Applications can request a 16-bit index buffer by including XrSceneMeshIndicesUint16MSFT in the XrSceneMeshBuffersMSFT::next chain. If the runtime for the given scene mesh buffer does not support requesting a 16-bit index buffer then XR_ERROR_VALIDATION_FAILURE must be returned. The runtime must support reading a 16-bit index buffer for the given scene mesh buffer if XrScenePlaneMSFT:supportsIndicesUint16 or XrSceneMeshMSFT:supportsIndicesUint16 are XR_TRUE for the scene component that contained that scene mesh buffer identifier.

The runtime must return XR_ERROR_SCENE_MESH_BUFFER_ID_INVALID_MSFT if none of the scene components in the given XrSceneMSFT contain XrSceneMeshBuffersGetInfoMSFT::meshBufferId. The runtime must return XR_ERROR_SCENE_MESH_BUFFER_ID_INVALID_MSFT if XrSceneMeshBuffersGetInfoMSFT::meshBufferId is zero. The runtime must return XR_ERROR_VALIDATION_FAILURE if both XrSceneMeshIndicesUint32MSFT and XrSceneMeshIndicesUint16MSFT are included in the XrSceneMeshBuffersMSFT::next chain. The runtime must return XR_ERROR_VALIDATION_FAILURE if the XrSceneMeshBuffersMSFT::next does not contain at least one of XrSceneMeshVertexBufferMSFT, XrSceneMeshIndicesUint32MSFT or XrSceneMeshIndicesUint16MSFT.

The runtime must return the same vertices and indices for a given scene mesh buffer identifier and XrSession. A runtime may return zero vertices and indices if the underlying mesh data is no longer available.

Valid Usage (Implicit)
Return Codes
On success, this command returns
  • XR_SUCCESS

  • XR_SESSION_LOSS_PENDING

On failure, this command returns
  • XR_ERROR_FUNCTION_UNSUPPORTED

  • XR_ERROR_VALIDATION_FAILURE

  • XR_ERROR_RUNTIME_FAILURE

  • XR_ERROR_HANDLE_INVALID

  • XR_ERROR_INSTANCE_LOST

  • XR_ERROR_SESSION_LOST

  • XR_ERROR_OUT_OF_MEMORY

  • XR_ERROR_SCENE_COMPONENT_ID_INVALID_MSFT

See Also

Document Notes

For more information, see the OpenXR Specification

This page is extracted from the OpenXR Specification. Fixes and changes should be made to the Specification, not directly.

Copyright (c) 2014-2021, The Khronos Group Inc.