AUI

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Attaching a view to the player ​

A view normally sits where you put its prefab in the scene. attach on <view> ties it to the local player instead. Everything here is local: each player sees their own copy move with themselves, and nothing is synced.

aui
<view name="Hud" width="150" height="80" attach="wrist-left" attach-corner="bottom-left">
  <text text="{credits}"/>
</view>

The modes ​

attachWhat the view does
wrist-left, wrist-rightsits at that hand in VR and shows while the player looks at it. On desktop it sits in attach-corner
cornerhead-locked in a corner of the player's view, for everyone
followfloats in front at eye level, and recentres only after the player turns or walks away
frontplaced straight ahead once, when the view is shown, then stays in the world
nonenot attached. Keeps the component so code can attach it later

Two more attributes go with it:

AttributeValuesApplies to
attach-cornerbottom-left (default), bottom-right, top-left, top-rightcorner, and a wrist view on desktop
attach-distancemetres from the head, 0.2 to 3, default 0.6corner, follow, front

Wrist ​

aui
<view name="Hud" width="150" height="80" attach="wrist-left" attach-corner="bottom-left">

The view sits a few centimetres above the hand and always faces the player's head. It appears while the hand is within 0.6 m of the head and the player is looking at it (within 24 degrees of the gaze), and disappears again past 36 degrees. The gap between the two angles stops it flickering at the edge. In practice: raise the hand and glance at it, like a watch.

It uses the hand's tracked position and never its rotation. The orientation of hand tracking data differs between controllers, and avatar bones differ between rigs, so a panel glued to a hand axis would sit differently for every player.

A player who is not in VR has no wrist, so the same view sits in its attach-corner.

Sizes are still millimetres. A wrist view is small, so give it small type: a 150 by 80 view with the default 18 mm body text holds very little.

Corner ​

aui
<view name="Status" width="150" height="80" attach="corner" attach-corner="top-right" attach-distance="0.6">

Head-locked, lying parallel to the view so it reads as a flat rectangle rather than one turned toward the eye.

On desktop it sits flush in that corner of the screen whatever the player's field of view and window shape, cornerMargin (3% of the screen height) in from the edges. It is placed at attach-distance, and pushed further out if the view would otherwise take more than cornerMaxFraction (90%) of the screen, so a large view shrinks to fit rather than hanging off the edge. Changing the FOV or resizing the window moves it on the next frame.

In VR there is no screen corner, so it is cornerAngles (27 and 15 degrees) sideways and up or down from the centre of the view. Head-locked panels are tiring in VR over a long session, which is why the wrist modes only use the corner on desktop.

Follow ​

aui
<view name="Welcome" width="440" height="300" attach="follow" attach-distance="1.2" start-hidden="true">

The view floats attach-distance ahead, 0.12 m below eye level, and stays level: it follows the direction the player faces, not where they tilt their head. It holds still until the player has turned more than 38 degrees away from it or walked more than 0.45 m, then glides to the new spot. Small head movements therefore never move it, and a button on it stays where the laser is pointing.

Front ​

aui
<view name="Notice" width="440" height="300" attach="front" attach-distance="0.8" start-hidden="true">

Show() and ShowInstant() place the view straight ahead of the player, facing them, and then it stays where it was put. The next Show() places it again. This is the placement the input panel uses for the keyboard target.

From code ​

csharp
SetAttach(ATTACH_FOLLOW);              // ATTACH_NONE, ATTACH_WRIST_LEFT, ATTACH_WRIST_RIGHT,
                                       // ATTACH_CORNER, ATTACH_FOLLOW, ATTACH_FRONT
SetAttachCorner(CORNER_TOP_RIGHT);
SetAttachDistance(1.2f);               // clamped to 0.2 .. 3
SetAttachOffset(new Vector3(0f, 0.09f, 0.03f));   // wrist: x right, y up, z toward the head
int mode = GetAttach();

These only work on a view whose markup has attach. The attribute is what makes the builder add the AuiAttach component to the prefab, and a component cannot be added in-world. A view that starts in the world and gets attached later declares that up front:

aui
<view name="Panel" width="440" height="300" attach="none">

Without it, SetAttach logs one warning and does nothing.

Tuning ​

The numbers on this page are defaults. They are public fields on the view's AuiAttach component: the wrist offset, range and angles, the corner angles, and the follow drop, angle, slack and speed. Set them in the inspector, on the prefab or on a scene instance. A rebuild rewrites only the mode, the corner and the distance, which come from the markup, and leaves the rest alone. The field table lists them.

Lasers ​

An attached view with no controls has its collider turned off, so it never stops a laser aimed past it. A view with buttons keeps its collider, and on a wrist it is on only while the view is visible.

AUI cannot choose which hand's laser reaches a view. A wrist view with buttons can therefore be pressed by the hand it sits on as well as by the other one.

Cost ​

An attached view runs a small update every frame while it is shown and moving with the player. A hidden view, attach="none", and a front view after its placement run nothing.

Nested views ​

Only an outermost view can be attached. A view used as a tag inside another view has no canvas of its own to move, so the builder drops its attach and the host reports AUI123. Place the attached view in the scene on its own, next to the view that would have hosted it, and wire the two through a typed reference.

Not verified yet ​

Attach compiles and its markup checks are tested, and that is all so far. It has not been run in the real client. Treat as unproven: where the wrist view lands and whether the glance thresholds feel right, lasers on a wrist view with buttons, jitter of corner and wrist views, how follow feels at its defaults, and the per-frame cost on Quest.

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