I had some problem with the egg script.
- It used fix chunk cells ( so the polygons would not get divided as well when there is high density)
- It left lots of empty collision nodes in the egg
- And most importantly guessing the cell size is hard! I have models in meters and never know weather its 1, .1 or 100… that was a big hindrance!
This script is a little faster too and provides command line interface. Try it out!
Some ideas for future implementation:
Limit the number of the smallest cell - why divide further if you will never fit through the hole.
Write the collision system back into the source egg.
Porting it to c++ (why bother its already super fast)
#!/usr/bin/python
"""
_
| |
___ __ _ __ _ ___ ___| |_ _ __ ___ ___
/ _ \/ _` |/ _` |/ _ \ / __| __| '__/ _ \/ _ \
| __/ (_| | (_| | (_) | (__| |_| | | __/ __/
\___|\__, |\__, |\___/ \___|\__|_| \___|\___|
__/ | __/ | by treeform
|___/ |___/
This is a replacement of raytaller wonderful
Egg Octree script many people had problem using it
( i always guessed wrong about the size of cells )
and it generated many "empty" branches which this
one does not.
original see : ( https://discourse.panda3d.org/viewtopic.php?t=2502 )
This script like the original also released under the WTFPL license.
Usage: egg-octreefy [args] [-o outfile.egg] infile.egg [infile.egg...]
-h display this
-v verbose
-l list resulting egg file
-n number of triangles per leaf (default 3)
if outfile is not specified "infile"-octree.egg assumed
"""
import sys, getopt
import math
from pandac.PandaModules import *
global verbose,listResultingEgg,maxNumber
listResultingEgg = False
verbose = False
maxNumber = 3
def getCenter(vertexList):
""" get a list of Polywraps and figure out their center """
# Loop on the vertices determine the bounding box
center = Point3D(0,0,0)
i = False
for vtx in vertexList:
center += vtx.center
i+=1
if i:
center /= i
return center
def flatten(thing):
""" get nested tuple structure like quadrents and flatten it """
if type(thing) == tuple:
for element in thing:
for thing in flatten(element):
yield thing
else:
yield thing
def splitIntoQuadrants(vertexList,center):
"""
+---+---+ +---+---+
| 1 | 2 | | 5 | 6 |
+---+---+ +---+---+
| 3 | 4 | | 7 | 8 |
+---+---+ +---+---+
put all poly wraps into quadrents
"""
quadrants = ((([],[]),
([],[])),
(([],[]),
([],[])))
for vtx in vertexList:
vtxPos = vtx.center
x = vtxPos[0] > center[0]
y = vtxPos[1] > center[1]
z = vtxPos[2] > center[2]
quadrants[x][y][z].append(vtx)
quadrants = flatten(quadrants)
return quadrants
class Polywrap:
"""
its a class that defines polygons center
so that it does not have to be recomputed
"""
polygon = None
center = None
def __str__(self):
""" some visualization to aid debugging """
return str(self.polygon.getNumVertices())+":"+str(self.center)
def genPolyWraps(group):
""" generate a list of polywraps form a group of polygons """
for polygon in iterChildren(group):
if type(polygon) == EggPolygon:
center = Vec3D()
i = False
for vtx in iterVertexes(polygon):
center += vtx.getPos3()
i += 1
if i : center /= i
pw = Polywrap()
pw.polygon = polygon
pw.center = center
yield pw
def buildOctree(group):
""" build an octree form a egg group """
global verbose
group.triangulatePolygons(0xff)
polywraps = [i for i in genPolyWraps(group)]
if verbose: print len(polywraps),"triangles"
center = getCenter(polywraps)
quadrants = splitIntoQuadrants(polywraps,center)
eg = EggGroup('octree-root')
for node in recr(quadrants):
eg.addChild(node)
return eg
def recr(quadrants,indent=0):
"""
visit each quadrent and create octree there
all the end consolidate all octrees into egg groups
"""
global verbose,maxNumber
qs = [i for i in quadrants]
if verbose: print " "*indent,"8 quadrents have ",[len(i) for i in qs]," triangles"
for quadrent in qs:
if len(quadrent) == 0:
if verbose: print " "*indent," no triangles at this quadrent"
continue
elif len(quadrent) <= maxNumber:
center = getCenter(quadrent)
if verbose: print " "*indent," triangle center", center, len(quadrent)
eg = EggGroup('leaf %i tri'%len(quadrent))
eg.addObjectType('barrier')
for pw in quadrent:
eg.addChild(pw.polygon)
if eg.getFirstChild : yield eg
else:
eg = EggGroup('branch-%i'%indent)
center = getCenter(quadrent)
for node in recr(splitIntoQuadrants(quadrent,center),indent+1):
eg.addChild(node)
if eg.getFirstChild : yield eg
def iterChildren(eggNode):
""" iterate all children of a node """
try:
child = eggNode.getFirstChild()
while child:
yield child
child = eggNode.getNextChild()
except:
pass
def iterVertexes(eggNode):
""" iterate all vertexes of polygon or polylist """
try:
index = eggNode.getHighestIndex()
for i in xrange(index+1):
yield eggNode.getVertex(i)
except:
index = eggNode.getNumVertices()
for i in xrange(index):
yield eggNode.getVertex(i)
pass
def eggLs(eggNode,indent=0):
""" list whats in our egg """
if eggNode.__class__.__name__ != "EggPolygon":
print " "*indent+eggNode.__class__.__name__+" "+eggNode.getName()
for eggChildren in iterChildren(eggNode):
eggLs(eggChildren,indent+1)
def eggStripTexture(eggNode):
""" strip textures and materials """
if eggNode.__class__ == EggPolygon:
eggNode.clearTexture()
eggNode.clearMaterial()
else:
for eggChildren in iterChildren(eggNode):
eggStripTexture(eggChildren)
def octreefy(infile,outfile):
"""
octreefy infile and write to outfile
using the buildOctree functions
"""
egg = EggData()
egg.read(Filename(infile))
eggStripTexture(egg)
group = egg
vertexPool = False
# find the fist group and fine the first vertexPool
# you might have to mess with this if your egg files
# are in odd format
for child in iterChildren(egg):
if type(child) == EggVertexPool:
vertexPool = child
if type(child) == EggGroup:
group = child
# if we have not found the vertexPool it must be inside
if not vertexPool:
for child in iterChildren(group):
if type(child) == EggVertexPool:
vertexPool = child
if vertexPool and group:
ed = EggData()
ed.setCoordinateSystem(egg.getCoordinateSystem())
ed.addChild(vertexPool)
ed.addChild(buildOctree(group))
if listResultingEgg: eggLs(ed)
ed.writeEgg(Filename(outfile))
def main():
""" interface to our egg octreefier """
try:
optlist, list = getopt.getopt(sys.argv[1:], 'hlvo:n:')
except Exception,e:
print e
sys.exit(0)
global verbose,listResultingEgg,maxNumber
outfile = False
for opt in optlist:
if opt[0] == '-h':
print __doc__
sys.exit(0)
if opt[0] == '-l':
listResultingEgg = True
if opt[0] == '-v':
verbose = True
if opt[0] == '-n':
maxNumber = int(opt[1])
if opt[0] == '-o':
outfile = opt[1]
if outfile and len(list) > 1:
print "error can have an outfile and more then one infile"
sys.exit(0)
for file in list:
if '.egg' in file:
if verbose: print "processing",file
if outfile:
octreefy(file,outfile)
else:
octreefy(file,file.replace(".egg","-octree.egg"))
if __name__ == "__main__":
import os
main()