better preview on pivot, with axes

app/helpers/helpers3D.module.js

@@ -77,6 +77,37 @@ app.helpers.helpers3D = {
             controls.target.copy(center)
             controls.update()
         }
-    }
+    },
+    
+    getObjectCenter(object) {
+        object.updateWorldMatrix(true, true)
+        const box = new THREE.Box3().setFromObject(object)
+        const center = new THREE.Vector3()
+        box.getCenter(center) // world coords
+        return center
+    },
+    
+    makePivotAtGeomCenter(object, scene) {
+        object.updateWorldMatrix(true, true)
+        const box = new THREE.Box3().setFromObject(object)
+        const centerW = box.getCenter(new THREE.Vector3())
+        
+        // Create pivot at world center of the object
+        const pivot = new THREE.Object3D()
+        pivot.position.copy(centerW)
+        pivot.matrixAutoUpdate = true
+        scene.add(pivot)
+        
+        // Compute the center in the object's local space
+        const centerLocal = object.worldToLocal(centerW.clone())
+        
+        // Shift the object so its center sits at its own origin
+        object.position.sub(centerLocal)
+        
+        // Reparent under the pivot (world pose preserved)
+        pivot.add(object)
+        
+        return pivot
+    },
     
 }

app/views/editors/modules/agentPreview.module.js

@@ -40,16 +40,19 @@ export class AgentPreview{
     }
 
     setAgent(id){ 
-        if(this.currentAgentObj && (this.scene.children.includes(this.currentAgentObj))){
+        if(this.pivot && (this.scene.children.includes(this.pivot))){
-            this.scene.remove(this.currentAgentObj)
+            this.scene.remove(this.pivot)
         }
         const agentSprite = this.agentSprites.find(item => item.atp_id==id)       
         if(!agentSprite) return
         this.currentAgentObj = this.agentFromJSON('previewedAgent', agentSprite.asp_3d)
-        this.currentAgentObj.position.set(0, 0, 0)
-        this.scene.add(this.currentAgentObj)
         
-        this.cameraAutoFrame(this.currentAgentObj, this.camera, 2)
+        this.pivot = this.makePivotAtGeomCenter(this.currentAgentObj, this.scene)
+        this.cameraAutoFrame(this.pivot, this.camera, 1.5)
+
+        // After creating the pivot, so axes do not unbalance the center, 
+        // and after cameraFraming so axes we frame on the object, no matter the axes
+        this.currentAgentObj.add(new THREE.AxesHelper(2))
     }
 
     set animation(value){
@@ -63,9 +66,9 @@ export class AgentPreview{
 
     _animate = () => {  // to avoid having to bind(this) in requestAnimationFrame, because one bound fn per frame = continuous GC load
         requestAnimationFrame(this._animate)
-        if(this.currentAgentObj && this.animation){
+        if(this.pivot && this.animation){
-            this.currentAgentObj.rotation.x += 0.005
+            this.pivot.rotation.x += 0.005
-            this.currentAgentObj.rotation.y += 0.01
+            this.pivot.rotation.y += 0.01
         }
         this.renderer.render(this.scene, this.camera)
     }

app/views/editors/modules/kfArena.module.js

@@ -50,7 +50,7 @@ export class kfArena{
         this.basePlane.position.y=-0.01 // to avoid artefacts on objets bases
         this.scene.add(this.basePlane)        
 
-        this.axes = new THREE.AxesHelper(this.sceneSize.x/2, this.sceneSize.y/2)
+        this.axes = new THREE.AxesHelper(this.sceneSize.x/2)
         this.axes.layers.set(2)
         this.scene.add(this.axes)