Finding vrdGeometryNode nodes in the scenegraph.
The traversal stops at shell geometries, shell components are not visited.
Here, we explicitly collect only nodes of type vrdGeometryNode.
Of course, a similar traversal method can be written that collects
other types of nodes or nodes based on a different criterion.
def findGeosRecursive(node, geos, predicate):
""" Recursively traverses the scenegraph starting at node
and collects geometry nodes which can be filtered
with a predicate.
Args:
node (vrdNode): Currently traversed node
geos (list of vrdGeometryNode): List of collected geometry nodes
predicate (function): None or predicate(vrdGeometryNode)->bool
"""
geo = vrdGeometryNode(node)
if geo.isValid():
if predicate is None or predicate(geo):
geos.append(geo)
# stop traversing the tree
else:
# traverse the children
for child in node.getChildren():
findGeosRecursive(child, geos, predicate)
def findGeos(root, predicate=None):
""" Wraps findGeosRecursive to return the list of geometry nodes.
"""
geos = []
findGeosRecursive(vrdNode(root), geos, predicate)
return geos
Using findGeos with predicate function to filter for line geometries:
def findLineGeos(root):
predicate = lambda geo : GeometryAccess.isLineType(geo.getPrimitiveType())
lines = findGeos(root, predicate)
return lines
Using findGeos to find B-side geometries:
bSideGeos = findGeos(root, lambda geo : geo.isBSide())