def clip_surface():
"""Clip the stl model."""
if not check_surface():
return
itemlist = [['axis',0],['begin',0.0],['end',1.0],['nodes','any']]
res,accept = widgets.inputDialog(itemlist,'Clipping Parameters').getResult()
if accept:
updateGUI()
nodes,elems = PF['old_surface'] = PF['surface']
F = Formex(nodes[elems])
bb = F.bbox()
GD.message("Original bbox: %s" % bb)
xmi = bb[0][0]
xma = bb[1][0]
dx = xma-xmi
axis = int(res[0][1])
xc1 = xmi + float(res[1][1]) * dx
xc2 = xmi + float(res[2][1]) * dx
nodid = res[3][1]
print nodid
clear()
draw(F,color='yellow')
w = F.test(nodes='any',dir=axis,min=xc1,max=xc2)
F = F.clip(w)
draw(F,clor='red')
