OrbitControls: Add 3D cursor and limit to orbit camera target. (#636)

types/three/examples/jsm/controls/OrbitControls.d.ts

@@ -44,6 +44,12 @@ export class OrbitControls extends EventDispatcher<OrbitControlsEventMap> {
     /** @deprecated */
     center: Vector3;
 
+    /**
+     * The focus point of the {@link .minTargetRadius} and {@link .maxTargetRadius} limits. It can be updated manually
+     * at any point to change the center of interest for the {@link .target}.
+     */
+    cursor: Vector3;
+
     /**
      * How far you can dolly in ( PerspectiveCamera only ).
      * @default 0
@@ -68,6 +74,18 @@ export class OrbitControls extends EventDispatcher<OrbitControlsEventMap> {
      */
     maxZoom: number;
 
+    /**
+     * How close you can get the target to the 3D {@link .cursor}.
+     * @default 0
+     */
+    minTargetRadius: number;
+
+    /**
+     * How far you can move the target from the 3D {@link .cursor}.
+     * @default Infinity
+     */
+    maxTargetRadius: number;
+
     /**
      * How far you can orbit vertically, lower limit.
      * Range is 0 to Math.PI radians.