anchor.diff:              // axes model space is (0,0,0)..(100,100,100)
               _axesObject = new AxesObject();
               Vector3 a = new Vector3(100.0, 100.0, 100.0);
  -            Vector3 b = renderTarget.len.clone();
  +            Vector3 b = renderSource.len.clone();
               Vector3 c = b.divide(a).scale(1.0 / 4.0);
               var axesModelToWorld = new Matrix4.identity().scale(c);
               _axesObject.applyMatrix(axesModelToWorld);
  
positive.code:         }
  
          {
              // when we set the cloud, we need to set the camera relative to it
              // position is returned in model space
              _cameraEyePoint = RenderUtils.getCameraPointEye(renderTarget);
              _cameraTargetPoint = RenderUtils.getCameraPointTarget(renderTarget);
  
              // move position to world space
              _cameraEyePoint.applyProjection(modelToWorld);
              _cameraTargetPoint.applyProjection(modelToWorld);
              _cameraUpVector = new Vector3(0.0, 0.0, 1.0);
  
              _addCamera();
              goHome();
  
negative.code:         //_cameraControls.dynamicDampingFactor = 0.3;
      }
  
      void setSource(RenderSource renderSource) {
          _renderTarget = renderSource;
  
          // model space ...(xmin,ymin,zmin)..(xmax,ymax,zmax)...
          // world space ...(0,0)..(xlen,ylen)...
          //
          // min point of the model becomes the origin of world space
  
          modelToWorld = new Matrix4.identity();
          modelToWorld.translate(-renderSource.min);
  
          {
              _particleSystem = RenderUtils.drawPoints(renderSource);
              _particleSystem.applyMatrix(modelToWorld);
              _scene.add(_particleSystem);
          }
  