API reference

OVROverlayCanvas Class

Renders UI as VR overlays composited by the VR runtime at native resolution for improved quality and performance.

Supports dynamic resolution scaling, frustum culling, and both flat and curved surfaces.

Fields

compositionMode : CompositionMode	Defines how the overlay is composited with with the scene layer. Punch-A-Hole creates a transparent hole in the scene, where the layer is rendered behind and peeks through the hole. Depth Tested renders in front of the scene, using the scene depth to determine where the layer has been occluded. Signature CompositionMode compositionMode
curveRadius : float	Radius of the cylindrical surface when shape is set to Curved. Larger values create less pronounced curves. Only affects curved overlays. Signature float curveRadius
depthRange : float	Depth range (in meters) in front of and behind the canvas plane that children may occupy. In 3D mode (enable3D) drives the off-axis frustum: near plane is placed at `dCanvas - depthRange` (clamped to a minimum of 0.05m so the canvas itself is never clipped when the eye gets very close) and far plane at `dCanvas + depthRange`. In 2D mode it sets the orthographic depth slab around the canvas plane. Defaults to 0.5m, which comfortably covers extruded-button-style UI parallax. Hidden from the inspector because the default is suitable for typical UI; settable programmatically. Signature float depthRange
enable3D : bool	Renders this canvas stereoscopically with proper per-eye parallax for 3D children. Flat shape only. Uses an off-axis projection from each eye position; content at the canvas plane is pixel-identical to the standard 2D path, content in front/behind shifts in screen space. The render texture is allocated double-wide and submitted as a Mono compositor layer with per-eye srcRects. Requires shape = CanvasShape.Flat; on Curved shapes 3D is silently disabled with a one-shot warning. Forces per-frame rendering: manualRedraw and renderInterval are ignored. Mipmap rendering is also disabled (mip 0 only per eye). Signature bool enable3D
layer : int	Unity layer used for rendering overlay content. Objects on this layer will be included in the overlay rendering. Default is layer 5. Signature int layer
manualRedraw : bool	When true, disables automatic rendering and requires manual calls to trigger updates. Use this for UI that changes infrequently to optimize performance. Signature bool manualRedraw
maxTextureSize : int	Maximum texture resolution (width or height) used for the overlay render texture. Higher values provide better quality but consume more memory and performance. Actual resolution may be lower based on dynamic scaling and aspect ratio. Signature int maxTextureSize
opacity : DrawMode	Defines how the overlay is rendered and composited with transparency handling. Controls whether content is opaque, transparent, or uses alpha clipping. Signature DrawMode opacity
overlapMask : bool	When enabled, creates an overlap mask to handle interactions between multiple overlays. Helps prevent visual artifacts when overlays intersect. Signature bool overlapMask
rectTransform : RectTransform	The RectTransform component that defines the canvas size and positioning. Must be on the same GameObject as the OVROverlayCanvas component. Signature RectTransform rectTransform
renderInterval : int	Interval between render updates in frames. Higher values reduce performance cost but make animations less smooth. Set to 1 for every frame, 2 for every other frame, etc. Signature int renderInterval
renderIntervalFrameOffset : int	Frame offset for render interval timing. Allows staggering updates across multiple overlay canvases to distribute performance load more evenly. Signature int renderIntervalFrameOffset
shape : CanvasShape	Geometric shape of the overlay surface. Flat creates a rectangular quad, while Curved creates a cylindrical surface with configurable radius. Signature CanvasShape shape
superSample : bool	Enables super sampling for improved visual quality at the cost of performance. Renders at 2x resolution internally, then scales down for sharper results. Use sparingly and only when visual quality is critical. Signature bool superSample

Protected Properties

rectTransformWorldCenter : Vector3

[Get]

Signature

Vector3 rectTransformWorldCenter

Properties

CanvasDepth : int [Get]	Signature virtual int CanvasDepth
expensive : bool [Get][Set]	Signature bool expensive
IsCanvasPriority : bool [Get]	Signature virtual bool IsCanvasPriority
Overlay : OVROverlay [Get]	Signature OVROverlay Overlay
overlayEnabled : bool [Get][Set]	Signature bool overlayEnabled
overlayType : OVROverlay.OverlayType [Get][Set]	Signature OVROverlay.OverlayType overlayType
ShouldShowImposter : bool [Get]	Signature bool ShouldShowImposter

Protected Methods

ShouldRender ()

Signature

virtual bool ShouldRender()

Returns

bool

Methods

GetViewDistance ()	Signature float? GetViewDistance() Returns `float?`
GetViewPriorityScore ()	Signature float? GetViewPriorityScore() Returns `float?`
GetWorldIntersectionFromCanvas ( canvasInstersectionPosition , intersectionPosition , intersectionNormal )	Signature void GetWorldIntersectionFromCanvas(Vector3 canvasInstersectionPosition, out Vector3 intersectionPosition, out Vector3 intersectionNormal) Parameters `canvasInstersectionPosition: Vector3` `intersectionPosition: out Vector3` `intersectionNormal: out Vector3` Returns `void`
SetCanvasLayer ( layer , forceUpdate )	Signature void SetCanvasLayer(int layer, bool forceUpdate) Parameters `layer: int` `forceUpdate: bool` Returns `void`
SetFrameDirty ()	Signature void SetFrameDirty() Returns `void`
TransformRay ( ray )	Signature override Ray TransformRay(Ray ray) Parameters `ray: Ray` Returns `override Ray`
UpdateOverlaySettings ()	Signature void UpdateOverlaySettings() Returns `void`

Inner Enums

DrawMode Enum

Defines how the overlay content is rendered and composited with the scene.

Controls transparency handling, clipping behavior, and alpha processing.

Enumeration Constants

Member	Value	Description
Opaque	0	Renders content as fully opaque without transparency support.
OpaqueWithClip	1	Renders opaque content with alpha clipping support for sharp edges.
Transparent	2	Renders content with full transparency and alpha blending support.
TransparentDefaultAlpha	2	Legacy transparency mode. Use Transparent instead.
TransparentCorrectAlpha	3	Legacy transparency mode with corrected alpha. Use Transparent instead.
AlphaToMask	4	Converts alpha values to binary mask for sharp transparency cutoffs.

CanvasShape Enum

Defines the geometric shape of the overlay surface.

Enumeration Constants

Member	Description
Flat	Renders on a flat rectangular surface.
Curved	Renders on a curved cylindrical surface with configurable radius.

CompositionMode Enum

Defines how the overlay is composited with the scene geometry.

Controls depth testing behavior and rendering order.

Enumeration Constants

Member	Value	Description
PunchAHole	OVROverlay.OverlayType.Underlay	Creates a hole in the scene where the overlay appears, allowing overlay content to show through. This composition mode is more efficient on the GPU, and handles occlusion by transparent objects more correctly, however artifacts may appear around the edges of the layer, and fine edge details will be lost.
DepthTested	OVROverlay.OverlayType.Overlay	Renders overlay with depth testing against the scene's depth buffer, The appearance of this layer's edges will be crisper without artifacts, however, the GPU cost is slightly higher, and occlusions by objects in the scene may show aliased edges and MSAA artifacts. Additionally, transparent objects will either not occlude the layer, or not blend correctly, depending on whether they write depth.