Vec4 ptC = this.computePoint(dc, posC, true);
if (f.contains(ptC))
return true;
double r = Line.distanceToSegment(ptA, ptB, ptC);
Cylinder cyl = new Cylinder(ptA, ptB, r == 0 ? 1 : r);
return cyl.intersects(dc.getView().getFrustumInModelCoordinates());
}