+ j = this.getY_withSign(j + step[1]);
+ if (j < 0) {
+ // Boundary between segments (cylinder mode)
+ j = -j;
+ segEnd = oldIJ;
+ segments.push(JSON.parse(JSON.stringify([segStart, segEnd])));
+ segStart = [];
+ }
+ else if (segStart.length == 0)
+ segStart = oldIJ;