getMatrixAt returns undefined

Questions
1

Hi i am trying to getMatrixAt but it keeps returning undefined what am I missing?


import * as THREE from './three/build/three.module.js';
import {entity} from './entity.js';
import {GLTFLoader} from './three/examples/jsm/loaders/GLTFLoader.js';


export const scenery_controller = (() => {
let mesh;
const count = 600;
const dummy = new THREE.Object3D();

class SceneryController extends entity.Component {
   constructor(params) {
     super();
     this.params_ = params;
     this.center_ = null;
     this.crap_ = [];
   }

   InitEntity() {
     this.SpawnShit_();
   }

   SpawnShit_() {
     const loader = new GLTFLoader();
     loader.load("./resources/nature2/GLTF/Cloud1.glb", function (geometry) {
     console.log(geometry);
      let geometry_ = geometry.scene;
       geometry_.traverse(function (child) {
         if (child.isMesh) {
           let material = new THREE.MeshBasicMaterial({ color: 0xff0000 });
           child.material = material;
           mesh = new THREE.InstancedMesh(child.geometry, child.material, count);
              mesh.instanceMatrix.setUsage(THREE.DynamicDrawUsage);
             scene.add(mesh);
           for (let i = 0; i < count; i++) {
             dummy.position.y = 0;
             dummy.position.set(0 +
               (Math.random() * 2.0 - 1.0) * 15,
               0,
               0 + (Math.random() * 2.0 - 1.0) * 16
             );
            
             dummy.rotation.y = 0 + Math.random();
             dummy.rotation.z = dummy.rotation.y * 2;
     
             dummy.updateMatrix();
     
             mesh.setMatrixAt(i++, dummy.matrix);
           }
         }
       });
      });
   }

 SpawnCrap_() {
     // anytime the player moves
     // SpawnCrap_() will be called.

     const player = this.FindEntity('player');
     if (!player) {
       return;
     }
     const pos = player._position;
     const center = new THREE.Vector3().copy(player.Position);
     center.x = Math.round(center.x / 2);
     center.y = 0.0;
     center.z = Math.round(center.z / 2);

     if (this.center_ && this.center_.equals(center)) {
       return;
     }
    this.center_ = center;
    let _P = new THREE.Vector3();
     const _V = new THREE.Vector3();
     const terrain = this.FindEntity('terrain').GetComponent('TerrainChunkManager');
     
     if (mesh) {
     for (let i = 0; i < count; i++) {
       
         const x = (Math.random() * 2.0 - 1.0) * 85;
         const y = (Math.random() * 2.0 - 1.0) * 85;
         _P.set(x, 0.0, y);
         _P.add(pos);
         _P.y = terrain.GetHeight(_P)[0];
    const scaler = (Math.random() * (0.720 - 2.200) + 2.200).toFixed(3);
    
    dummy.scale.set( 
    scaler, scaler, scaler
     );
   
     dummy.position.set( 
        _P.x,
        _P.y,
        _P.z
      );

  // dummy.scale.set(0,0,0)
   dummy.updateMatrix();
   mesh.instanceMatrix.needsUpdate = true;
   dummy.rotation.y = 0 + Math.random();
   dummy.rotation.z = dummy.rotation.y * 2;
  
   dummy.updateMatrix();

   mesh.setMatrixAt(i++, dummy.matrix);

   // gm returns undefined 
   // i suspect dummy.matrix isnt the right thing to go here..
   let gm =  mesh.getMatrixAt( i++, dummy.matrix );
   console.log(gm, 'get instanced mesh');
  
     }
     }

   }
 Update(_) {
     this.SpawnCrap_();
   }
 };

 return {
     SceneryController: SceneryController,
 };
})();

thank you for any help

2

When in doubt, read the docs . Retuning undefined is the expected behaviour, the matrix you pass as an argument to that method will be set to the corresponding ,atrix.

3

Also, it may be worth installing types for three. I believe they even without typescript your IDE could be of help here. Could save you some time browsing the docs.

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