Anchor
- Last UpdatedFeb 19, 2025
- 3 minute read
The Anchor node specifies a transform to place a mesh and an object in AR world space. This helps to track the real world positions of your virtual content. Anchor node is designed to persist mesh and object in AR world space across app sessions.
The Anchor node is not a standalone node, but is used with ARKitManager or ARCoreManager nodes. These nodes manage anchors in the iOS and Android platforms respectively.
Platform support
This node is supported on XR-Portable iOS, but partially supported on XR-Portable Android. It is not supported on Windows, Portable Windows or WASM.
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XR-WIN |
XR-P-WIN |
XR-P-IOS |
XR-P-AND |
XR-P-WASM |
|---|---|---|---|---|
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No support |
No support |
Full support |
Partial support |
No support |
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Managing Anchors in different platforms
After an anchor is created using the Anchor node, a similar platform specific anchor object is created in ARKitManager or ARCoreManager.
In the case of iOS, the anchors are saved to the ARKit world map using the ARKitManager saveWorldMap field. In the next app session, the world map can be loaded using the ARKitManager loadWorldMap event and can retrieve all the anchors using the ARKitManager loadedAnchors field.
In the case of Android, the AR Anchors are created and added to the ARCoreManager session.
Note: ARKitManager persists Anchor in AR world space across app sessions. However, at present, ARCoreManager cannot persist Anchors across various app sessions. It could persist Anchors across various AR sessions though.
Anchor fields
These are the fields for the Anchor node. Only the node-specific fields are indicated, not fields obtained by inheritance.
Field inheritance: NodeBase > Anchor
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Fields |
Type |
Use |
Default |
Description |
|---|---|---|---|---|
|
offsetMatrix |
smatrix |
Optional |
Identity |
This matrix field specifies offset position and orientation of a mesh or an object at the Anchor location. |
|
localMatrix |
smatrix |
Mandatory |
Identity |
Specifies the anchor’s position and orientation in AR world space while creating an Anchor. In subsequent app sessions, this field will be automatically be updated by the platform specific AR manager node (ARKitManager or HololensSensor). |
|
object |
sstring |
Optional |
Specifies the 3D object name which is transformed to the anchor’s position and orientation. |
|
|
mesh |
sstring |
Mandatory |
Specifies the mesh name which is transformed to the anchor’s position and orientation. |