C Specification

The XrScenePlaneMSFT structure represents the state of a scene plane.

It is defined as:

typedef struct XrScenePlaneMSFT {
    XrScenePlaneAlignmentTypeMSFT    alignment;
    XrExtent2Df                      size;
    uint64_t                         meshBufferId;
    XrBool32                         supportsIndicesUint16;
} XrScenePlaneMSFT;


Member Descriptions
  • alignment is the alignment type of the plane specified by XrScenePlaneAlignmentTypeMSFT.

  • size is the 2D size of the plane’s extent, where size::width is the width of the plane along the X axis, and size::height is the height of the plane along the Y axis.

  • meshBufferId is the uint64_t identifier that specifies the scene mesh buffer of this plane’s triangle mesh. If meshBufferId is zero then this plane does not have a mesh. The triangles in a planar mesh are coplanar.

  • supportsIndicesUint16 is XR_TRUE if the mesh supports reading 16-bit unsigned indices.


The size of a plane refers to the plane’s size in the x-y plane of the plane’s coordinate system. A plane with a position of {0,0,0}, rotation of {0,0,0,1} (no rotation), and an extent of {1,1} refers to a 1 meter x 1 meter plane centered at {0,0,0} with its front face normal vector pointing towards the +Z direction in the plane component’s space. For planes with an alignment of XR_SCENE_PLANE_ALIGNMENT_TYPE_VERTICAL_MSFT, the +Y direction must point up away from the direction of gravity.

xr msft scene understanding plane coordinate system
Figure 1. Scene Understanding Plane Coordinate System

OpenXR uses an X-Y plane with +Z as the plane normal but other APIs may use an X-Z plane with +Y as the plane normal. The X-Y plane can be converted to an X-Z plane by rotating -π/2 radians around the +X axis.

Valid Usage (Implicit)

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.

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