message: fix boundary-helper regression
diff: @@ -13,6 +13,7 @@ import { Box3D } from './primitives/box3d';
  const v3dot = Vec3.dot;
  const v3copy = Vec3.copy;
  const v3scaleAndSub = Vec3.scaleAndSub;
  +const v3scaleAndAdd = Vec3.scaleAndAdd;
  // implementing http://www.ep.liu.se/ecp/034/009/ecp083409.pdf
  @@ -48,7 +49,7 @@ export class BoundaryHelper {
  }
  if (d + radius > this.maxDist[i]) {
  this.maxDist[i] = d + radius;
  - v3scaleAndSub(this.extrema[i * 2 + 1], center, di, radius);
  + v3scaleAndAdd(this.extrema[i * 2 + 1], center, di, radius);
  }
  }
  