Function applyTransform

js/mapping.js:319–329

(u, v, scaleU, scaleV, offsetU, offsetV, cosR, sinR)

      const ax2 = ax * ax, ay2 = ay * ay, az2 = az * az;
      const bx = ax2 * ax2;
      const by = ay2 * ay2;
      const bz = az2 * az2;
      const sum = bx + by + bz + 1e-6;
      const wx = bx / sum;
      const wy = by / sum;
      const wz = bz / sum;

      // Flip U based on normal sign so opposite faces show correct (non-mirrored) text.
      let yzU = (pos.y - min.y) / md;
      if (normal.x < 0) yzU = -yzU;
      let xzU = (pos.x - min.x) / md;
      if (normal.y > 0) xzU = -xzU;
      let xyU = (pos.x - min.x) / md;
      if (normal.z < 0) xyU = -xyU;