LookAt

A component that makes the current object's orientation follow a target's position or orientation.

Type	Name	Interface Description
Variables	directionAim: LookAtDirection	• Function: Gets the direction of the object that will point to the target.
Variables	directionUp: LookAtDirection	• Function: Gets the direction of the object that will be aligned with the world up direction.
Variables	mode: LookAtMode	• Function: Gets the mode for the look-at calculation.
Variables	offsetRotation: Vector3f	• Function: Gets An additional rotation applied after the look-at calculation. The value is in Euler angles.
Variables	target: Transform | null	• Function: Gets the transform of the target object to look at.
Variables	worldUp: LookAtWorldUp	• Function: Gets the world-up vector for the look-at calculation.
Functions	constructor()

Examples

constructor()

let obj = new APJS.LookAt();

Use Case

Object always faces the camera (billboard effect)

@component()
export class LookAtCamera extends APJS.BasicScriptComponent {
  onUpdate(deltaTime: number): void {
    const transform = this.getSceneObject().getTransform();
    const children = this.getSceneObject().parent?.getChildren() || [];

    // Find camera in scene
    for (const child of this.getSceneObject().parent?.getChildren() || []) {
      const cam = child.getComponent("Camera") as APJS.Camera;
      if (cam) {
        const camPos = child.getTransform().getWorldPosition();
        const myPos = transform.getWorldPosition();
        const dir = new APJS.Vector3f(
          camPos.x - myPos.x,
          0,
          camPos.z - myPos.z
        ).normalize();
        const angle = Math.atan2(dir.x, dir.z) * 180 / Math.PI;
        transform.localEulerAngles = new APJS.Vector3f(0, angle, 0);
        break;
      }
    }
  }
}