Problems with ArcballControls

scale

TypeError
Cannot assign to read only property 'scale' of object '#<ArcballControls>'
new ArcballControls
/src/ArcballControls.js:66:48
  63 |  * @param {Scene} scene The scene to be rendered
  64 |  */
  65 | class ArcballControls extends Object3D {
> 66 |   constructor(camera, domElement, scene = null) {

It extends Object3D which has made scale a configured prop that can’t be replaced, but then it defines a scale function. It should be renamed setScale as it is in conflict with the base class (O3D).

target

current arcball can’t be controlled generically from outside like other controls. this is because exposing this.target was not enough. it has a setTarget function that sets gizmos, and for some reason the update function takes the gizmo position into account, not the target.

changeset

i have made the necessary changes in three-stdlib but for the sake of coherency maybe it would be good to bring them over.

@@ -189,6 +189,8 @@ class ArcballControls extends Object3D {
 
     //trackball parameters
     this.target = new Vector3(0, 0, 0)
+    this._currentTarget = new Vector3(0, 0, 0)
+
     this._tbRadius = 1
 
-  /**
-   * Set the trackball's center point
-   * @param {Number} x X coordinate
-   * @param {Number} y Y coordinate
-   * @param {Number} z Z coordinate
-   */
-  setTarget = (x, y, z) => {
-    this.target.set(x, y, z)
-    this._gizmos.position.set(x, y, z) //for correct radius calculation
-    this._tbRadius = this.calculateTbRadius(this.camera)
-
-    this.makeGizmos(this.target, this._tbRadius)
-    this.camera.lookAt(this.target)
-  }
-
   /**
    * Set values in transformation object
    * @param {Matrix4} camera Transformation to be applied to the camera
@@ -2497,12 +2484,23 @@ class ArcballControls extends Object3D {
   update = () => {
     const EPS = 0.000001
 
+    if (!this.target.equals(this._currentTarget)) {
+      this._gizmos.position.set(this.target.x, this.target.y, this.target.z) //for correct radius calculation
+      this._tbRadius = this.calculateTbRadius(this.camera)
+      this.makeGizmos(this.target, this._tbRadius)
+      this._currentTarget.copy(this.target)
+    }
+

[drcmda]

no problem. will do it … just working on some other arcball issues i’m profiling right now, but will come back to this.

[Mugen87]

Feel free to create another PR with your fixes. However, removing setTarget() makes the controls more similar to the others so we wanted to do this anway.