Python in houdini

#메세지 툴박스 팝업후 실행
geo = hou.node("obj/").createNode("geo")
if hou.ui.displayMessage("BTW",buttons=("GRID","BOX"))==0:
    geo.createNode("grid")
else:
    geo.createNode("box")
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#파이썬 샵에서 파라미터 만든후 폴리곤 형성
geo = hou.pwd().geometry()
poly = geo.createPolygon()
num_=hou.Node.evalParm(hou.pwd(),"intnum")
pi_=hou.Node.evalParm(hou.pwd(),"pi")
import math
for x in range(num_):
    y=math.sin(x * math.pi * pi_ / num_) *5
    z=math.cos(x * math.pi * pi_ / num_) *5
    a=geo.createPoint()
    a.setPosition((0,y,z))
    poly.addVertex(a)