view.js

import {Group,Mesh2,PhysicalMaterial,PlaneGeometry,SphereGeometry,CapsuleGeometry,CylinderGeometry,BoxGeometry,BufferGeometry,Float32BufferAttribute,Matrix4,Color} from '@kite3d/engine'
// MuJoCo geom types: plane=0, hfield=1, sphere=2, capsule=3, ellipsoid=4, cylinder=5, box=6, mesh=7.
export class ModelView {
  constructor(description){
    this.root=new Group();this.root.name='MuJoCo model view';this.root.rotation.x=-Math.PI/2
    this.meshes=[];this.matrix=new Matrix4()
    try{
      for(const g of description.geometries){
        const s=g.size;let geometry
        if(g.type===0)geometry=new PlaneGeometry(2*Math.min(s[0]||3,1.4),2*Math.min(s[1]||3,1.4))
        else if(g.type===2)geometry=new SphereGeometry(s[0],24,16)
        else if(g.type===3){geometry=new CapsuleGeometry(s[0],2*s[1],8,16);geometry.rotateX(Math.PI/2)}
        else if(g.type===4){geometry=new SphereGeometry(1,24,16);geometry.scale(...s)}
        else if(g.type===5){geometry=new CylinderGeometry(s[0],s[0],2*s[1],24);geometry.rotateX(Math.PI/2)}
        else if(g.type===6)geometry=new BoxGeometry(2*s[0],2*s[1],2*s[2])
        else if(g.type===7){geometry=new BufferGeometry();geometry.setAttribute('position',new Float32BufferAttribute(g.vertices,3));geometry.setIndex(Array.from(g.faces));geometry.computeVertexNormals()}
        else throw Error(`MuJoCo visual geom type ${g.type} is not supported (${g.name})`)
        const material=new PhysicalMaterial({color:new Color().setRGB(...g.rgba.slice(0,3)),roughness:.65,metalness:0,transparent:g.rgba[3]<1,opacity:g.rgba[3],side:2})
        const mesh=new Mesh2(geometry,material);mesh.name=g.name;mesh.userData.mujocoGeomId=g.id
        this.meshes[g.id]=mesh;this.root.add(mesh)
      }
    }catch(error){this.dispose();throw error}
  }
  update(frame){
    const p=frame.geomPositions,r=frame.geomMatrices
    for(let i=0;i<this.meshes.length;i++){
      const mesh=this.meshes[i],b=i*9
      mesh.position.fromArray(p,i*3)
      this.matrix.set(r[b],r[b+1],r[b+2],0,r[b+3],r[b+4],r[b+5],0,r[b+6],r[b+7],r[b+8],0,0,0,0,1)
      mesh.quaternion.setFromRotationMatrix(this.matrix);mesh.updateMatrix()
    }
  }
  dispose(){this.root.removeFromParent();for(const mesh of this.meshes){mesh.geometry.dispose();mesh.material.dispose()}this.meshes=[];this.root.clear()}
}