C Specification

typedef enum XrViewConfigurationType {
    XR_VIEW_CONFIGURATION_TYPE_PRIMARY_MONO = 1,
    XR_VIEW_CONFIGURATION_TYPE_PRIMARY_STEREO = 2,
  // Provided by XR_VERSION_1_1
    XR_VIEW_CONFIGURATION_TYPE_PRIMARY_STEREO_WITH_FOVEATED_INSET = 1000037000,
  // Provided by XR_MSFT_first_person_observer
    XR_VIEW_CONFIGURATION_TYPE_SECONDARY_MONO_FIRST_PERSON_OBSERVER_MSFT = 1000054000,
  // Provided by XR_VARJO_quad_views
    XR_VIEW_CONFIGURATION_TYPE_PRIMARY_QUAD_VARJO = XR_VIEW_CONFIGURATION_TYPE_PRIMARY_STEREO_WITH_FOVEATED_INSET,
    XR_VIEW_CONFIGURATION_TYPE_MAX_ENUM = 0x7FFFFFFF
} XrViewConfigurationType;

Description

The application selects its primary view configuration type when calling xrBeginSession, and that configuration remains constant for the lifetime of the session, until xrEndSession is called.

The number of views and the semantic meaning of each view index within a given view configuration is well-defined, specified below for all core view configurations. The predefined primary view configuration types are:

Enumerant Descriptions

  • XR_VIEW_CONFIGURATION_TYPE_PRIMARY_MONO. One view representing the form factor’s one primary display. For example, an AR phone’s screen. This configuration requires one projection in each XrCompositionLayerProjection layer.

  • XR_VIEW_CONFIGURATION_TYPE_PRIMARY_STEREO. Two views representing the form factor’s two primary displays, which map to a left-eye and right-eye view. This configuration requires two views in each XrCompositionLayerProjection layer. View index 0 must represent the left eye and view index 1 must represent the right eye.

  • XR_VIEW_CONFIGURATION_TYPE_PRIMARY_STEREO_WITH_FOVEATED_INSET. Four views representing the form factor’s primary stereo displays. This view configuration type represents a hardware independent way of providing foveated rendering. The view configuration adds two foveated inset views for the left and right eye separately to the already defined two views specified in the XR_VIEW_CONFIGURATION_TYPE_PRIMARY_STEREO view configuration. View index 0 must represent the left eye and view index 1 must represent the right eye as specified in XR_VIEW_CONFIGURATION_TYPE_PRIMARY_STEREO view configuration, and view index 2 must represent the left eye inset view and view index 3 must represent the right eye inset view. The new inset view 2 and view 3 must, after applying the pose and FoV projection to same plane, be contained within view 0 and 1 respectively. The inset views may have a higher resolution with respect to the same field of view as the corresponding wide FoV view for each eye. The runtime may blend between the views at the edges, so the application must not omit the inner field of view from being rendered in the outer view. The fov returned by xrLocateViews for each inset view relative to the corresponding outer stereo view may change at run-time, the pose for inset view and stereo view for each eye respectively must have the same values.

Note

The benefits of the XR_VIEW_CONFIGURATION_TYPE_PRIMARY_STEREO_WITH_FOVEATED_INSET view configuration type can be demonstrated by looking at the rendered pixel count. For example, a Varjo Aero requires a pair of stereo views rendered at 4148 x 3556 (14.7 million pixels) to achieve a pixel density of 35 pixels per degree. By using four views, with an eye-tracked foveated inset covering about 1/9th of the full FoV and rendered with the same 35 pixels per degree and while the remaining views are dropped to 14 pixels per degree, the resolution of the inset is 1076 x 1076 (1.1 million pixels) and the resolution of the stereo views is 1660 x 1420 (2.3 million pixels). The total pixel count is 75% less with XR_VIEW_CONFIGURATION_TYPE_PRIMARY_STEREO_WITH_FOVEATED_INSET over the XR_VIEW_CONFIGURATION_TYPE_PRIMARY_STEREO view configuration type.

See Also

XrEventDataVisibilityMaskChangedKHR, XrSecondaryViewConfigurationLayerInfoMSFT, XrSecondaryViewConfigurationSessionBeginInfoMSFT, XrSecondaryViewConfigurationStateMSFT, XrSecondaryViewConfigurationSwapchainCreateInfoMSFT, XrSessionBeginInfo, XrViewConfigurationProperties, XrViewLocateInfo, xrEnumerateEnvironmentBlendModes, xrEnumerateReprojectionModesMSFT, xrEnumerateViewConfigurationViews, xrEnumerateViewConfigurations, xrGetViewConfigurationProperties, xrGetVisibilityMaskKHR

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

Copyright 2014-2025 The Khronos Group Inc.

This work is licensed under a Creative Commons Attribution 4.0 International License.