[Bf-python] Most efficient way to copy faces

[Toni Alatalo]

On May 28, 2009, at 11:11 AM, lynx.abraxas at freenet.de wrote:

> Well, is there a more efficient way to create the big list than 
> iterating over
> all potato.faces checking iteratively their verts if they are the same 
> as  one
> of  the inside.verts list? That way I have three nested for loops. I 
> wonder if
> there is a better way using pythons set check with in?

perhaps.

also a list comprehension might serve well there,
f = [f for f in mesh.faces if inside(x, f)] #or something like that

don't know about the efficiency but i suspect it's good for the case 
where you need to iterate, have a condition and are creating a new 
list.

> Lynx

~Toni

>> mesh.faces.extend().  Not sure how you handle UVs and the like though,
>> it's kindof a pain, I think.
>>
>> Joe
>>
>> On Sun, May 24, 2009 at 12:41 PM,  <lynx.abraxas at freenet.de> wrote:
>>> Hello,
>>>
>>>
>>>
>>> Next question: What is the most efficient way to copy faces from 
>>> another mesh?
>>> I have now the verts that lie within an ellipsoid and now I'd like 
>>> to copy the
>>> faces that belong to these verts. I'm doing it currently like this:
>>>
>>>
>>>
>>> if len(vin.verts) > 2: # we need at least one face => three verts 
>>> minimum
>>>      #find inside faces in potato to copy
>>>      for i in range(0, len(potmesh.faces)): #check all potato faces
>>>         nvi= 0
>>>         f= []
>>>         for j in range(0, len(potmesh.faces[i].verts)): #if all 
>>> verts of a face
>>>            for k in vin.verts: #are in the list of the inside verts
>>>               if k.co == potmesh.faces[i].verts[j].co:
>>>               #if k in potmesh.faces[i].verts:#this does not work! 
>>> why?
>>>                  nvi+= 1
>>>                  f.append(k)#create face with vin.verts indices!
>>>         if nvi == len(potmesh.faces[i].verts): #if all verts of a 
>>> potato face are in the inside verts list
>>>            vin.faces.extend(f) #add it to the list of insede faces
>>>         elif nvi > len(potmesh.faces[i].verts):
>>>            print "Potato mesh contains double verts!"
>>>            #vin.faces.extend(f) #only possible for 2 to 4 verts!
>>>         #else:
>>>         #   print "Face not completly inside ellipsoid."
>>>
>>>
>>> This  is  taking  a  long time for my big "potato" (3 million verts, 
>>> 1 million
>>> faces). Is there a better way to do this?
>>>
>>> Many thanks for any help or hints
>>> Lynx
>>>
>>>
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