Houdini Python SOP

Group_from_connected_edges_ordered.py

def checkConnectivity(e1, e2):
    chk = e1.points()[0].number == e2.points()[0].number
    chk = chk or e1.points()[0].number == e2.points()[1].number
    if chk: return 1
    chk = e1.points()[1].number == e2.points()[0].number
    chk = chk or e1.points()[1].number == e2.points()[1].number
    if chk: return 2
    return 0
    
def isNext(e1, e2):
    chk = e1.points()[0].number == e2.points()[1].number
    if chk: return 1
    chk = e1.points()[1].number == e2.points()[1].number
    if chk: return 2
    return 0

node = hou.pwd()
geo = node.geometry()

prefix = node.parm('prefix').eval().strip()
if prefix == '':
    prefix = 'edge'
else:
    prefix = prefix.replace(' ', '_')
    
ptn = node.parm('group').eval().strip()
#if ptn == '': ptn = '*'
if ptn != '': 
    edges = set( geo.globEdges(ptn) )
    
    oneside_edges = set()
    for e in edges:
        sideone = False
        sidetwo = False
        for testedge in edges:
            if e is testedge: continue
            
            chk = checkConnectivity(e, testedge)
            if chk == 1: sideone = True
            if chk == 2: sidetwo = True
            
            if sideone and sidetwo: break
        
        if sideone + sidetwo == 1:
            if sideone: oneside_edges.add( (e, 1) )
            if sidetwo: oneside_edges.add( (e, 2) )
    
    used_edges = set()
    def recursiveConnectedEdges(current, grp):
        unused = edges - used_edges # update unused for recursive
        for e in unused:
            unused = edges - used_edges # update unused for loop
            if e in unused:
                chk = isNext(e, current)
                if chk > 0:
                    used_edges.add(e)
                    
                    next_edge = e
                    if chk == 2:
                        next_edge = geo.findEdge(e.points()[1], e.points()[0])
                    grp.add(next_edge)
                    
                    recursiveConnectedEdges(next_edge, grp)
                    
    i = 1
    for e in oneside_edges:
        unused = edges - used_edges
        
        if e[0] in unused:
            used_edges.add(e[0])
            
            cur_edge = e[0]
            if e[1] == 1:
                cur_edge = geo.findEdge(cur_edge.points()[1], cur_edge.points()[0])
            
            grp = geo.createEdgeGroup( prefix + str(i) )
            grp.add(cur_edge)
            
            recursiveConnectedEdges(cur_edge, grp)
            i += 1
    
    rem = edges - used_edges
    for e in rem:
        unused = edges - used_edges
        if e in unused:
            used_edges.add(e)
            
            grp = geo.createEdgeGroup( prefix + str(i) )
            grp.add(e)
            
            recursiveConnectedEdges(e, grp)
            i += 1