message: MC: ensure winding-order and normals dir are same for neg/pos iso-level
diff: @@ -196,11 +196,16 @@ class MarchingCubesState {
  const n1y = sfg(sf, hi, Math.max(0, hj - 1), hk) - sfg(sf, hi, Math.min(this.nY - 1, hj + 1), hk);
  const n1z = sfg(sf, hi, hj, Math.max(0, hk - 1)) - sfg(sf, hi, hj, Math.min(this.nZ - 1, hk + 1));
  - this.builder.addNormal(
  - n0x + t * (n0x - n1x),
  - n0y + t * (n0y - n1y),
  - n0z + t * (n0z - n1z)
  - );
  + const nx = n0x + t * (n0x - n1x);
  + const ny = n0y + t * (n0y - n1y);
  + const nz = n0z + t * (n0z - n1z);
  +
  + // ensure normal-direction is the same for negative and positive iso-levels
  + if (this.isoLevel >= 0) {
  + this.builder.addNormal(nx, ny, nz);
  + } else {
  + this.builder.addNormal(-nx, -ny, -nz);
  + }
  return id;
  }
  @@ -255,7 +260,13 @@ class MarchingCubesState {
  const triInfo = TriTable[tableIndex];
  for (let t = 0; t < triInfo.length; t += 3) {
  - this.builder.addTriangle(this.vertList, triInfo[t], triInfo[t + 1], triInfo[t + 2], edgeFilter);
  + const l = triInfo[t], m = triInfo[t + 1], n = triInfo[t + 2];
  + // ensure winding-order is the same for negative and positive iso-levels
  + if (this.isoLevel >= 0) {
  + this.builder.addTriangle(this.vertList, l, m, n, edgeFilter);
  + } else {
  + this.builder.addTriangle(this.vertList, n, m, l, edgeFilter);
  + }
  }
  }
  }
  \ No newline at end of file
  