BoundsControl

Bounds Control is a component that allows the user to change the position, rotation, and size of an actor, using affordances. Affordances are grabbable areas on corners (scale), edges (rotate), and faces (translate) of the actor's bounding box.

To enable bounds control on an actor, add an UUxtBoundsControlComponent to it. The component has a default configuration that can be tweaked to change the behavior and appearance as needed.

BoundsControlComponent

Bounds Control Config

UxtBoundsControlConfig data assets are used to configure:

  • Affordances array. Each has:
    • Placement. Enumerator with the position of the affordance around the actor. For example, CornerFrontTopLeft, EdgeBottomRight or FaceBack. See EUxtAffordancePlacement for a complete list.
    • Rotation of the instanced mesh.
  • IsSlate. Whether it should be considered a 2D element or not. If so, it won't scale along the X axis.
  • UniformScaling. Whether uniform or non-uniform scaling is desired.

There are some presets in BoundsControl/Presets:

  • BoundsControlDefault: All corner and edge affordances with uniform scaling.
  • BoundsControlSlate2D: Only front corners and edges, with non-uniform scaling.

Integration with manipulator constraints

The UUxtBoundsControlComponent works out of the box with the same constraint components that Manipulators use. For example, simply adding and configuring a UUxtRotationAxisConstraint component will prevent rotation around the appropriate axes when interacting via affordances.

Affordance meshes

At runtime a separate actor is created for displaying affordances. Each affordance is a StaticMesh component on the BoundsControlActor. The mesh used for each kind of affordance (Corner, Edge, Face, Center) can be changed on the bounds control component (Corner Affordance Mesh etc.).

When creating custom affordance meshes you can fine tune the orientation of each affordance by duplicating one of the preset layouts and modifying the Rotation properties. It is recommended to use simple box collision primitives to make affordances grabbable.