Hi,
I know there is a “method” (or is it a method ???) in the material module of the API to get the number of users of a material datablock.
But is there a simple way to get a list of these users ?
Or do I have to do it the reversed way and iterate over all the objects/meshes/surfaces/metaballs etc and add them to a list if they are linked to the material i am interested in ?
You choose which strategy you’re to implement… Just start it… Otherwise you’ll hardly have the issue solved! 
I’d be glad to see your solution 
Regards,
You may want to examine the LuxBlend exporter script, I think it populates a drop down box with materials in the scene.
No use re-inventing the wheel.
Well I can easily create a list of all the material used in the scene, that is dead easy.
What is more tricky (or it seems so…) is to get the list of objects or meshes linked to a particular material.
It seems I have to test all objects of the scene.
But i think I had to do that in the past: i may find the solution in one of my own script
i wrote a script that will “select by material”… in object mode it’ll select all the objecxts that use the material you choose, in edit mode it’ll select all the faces that use the material in the active object…
and yes, you do have to iterate through all objects in the scene…
#!BPY
"""
Name: 'Find Items with Material'
Blender: 234
Group: 'Object'
Tooltip: 'In object mode: selects all objects with the chosen material/n in edit mode selects faces.'
"""
import bpy
from Blender import *
from Blender import Scene, Mesh, Window, sys
import BPyMessages
#late version!
def getAllMaterials(is_editmode):
matlist =[]
if is_editmode:
scn = bpy.data.scenes.active
ob_act = scn.objects.active
me = ob_act.getData(mesh=1)
mats= me.materials
for m in mats:
matlist.append(m.name)
return matlist
else:
for mat in bpy.data.materials:
matlist.append(mat.name)
return matlist
def ui(is_editmode):
#create a menu for the user to pick materials from
#get the existing materials
matlist = getAllMaterials(is_editmode)
pupmessage = "Select Objects With Material:%t"
if is_editmode:
pupmessage = "Select Faces With Material:%t"
Puplist = pupmessage
for mat in matlist:
Puplist+= "|"+ mat
#Ok, make the menu
chan = Draw.PupMenu(Puplist,30)
if chan != -1: #something was chosen process it
try:
material = matlist[chan-1]
print"chosen Material is", material
return material
except:
return none
def findMaterial(matToFind):
is_editmode = Window.EditMode()
scn = bpy.data.scenes.active
if is_editmode:
Window.EditMode(0)
#only current object
ob_act = scn.objects.active
me = ob_act.getData(mesh=1)
mats = me.materials
if mats:
i=0
matindex = 0
for m in mats:
if m.name == matToFind:
matindex = i
break
i += 1
for f in me.faces:
f.sel = False
if f.mat == matindex:
f.sel = True
else:
f.sel = False
else:
print "no mats on mesh"
me.update()
Window.EditMode(is_editmode)
else:
#check each scene starting with current:
scn = bpy.data.scenes.active
print "----------------"
for ob in scn.objects:
ob.sel = False
try:
if not ob.lib and ob.type == 'Mesh': # object isn't from a library and is a mes
me = ob.getData(mesh=1)
mats = me.materials
if len(mats) >= 1:
for m in mats:
if m.name == matToFind:
ob.sel = True
print("found %s in object " %matToFind, ob.name)
break
else:
ob.sel = False
except:
print "error with" ,ob.name
continue
Window.WaitCursor(0)
#Draw.PupMenu('Material "%s" Not found.' % matToFind)
def main():
is_editmode = Window.EditMode()
matToFind = ui(is_editmode)
if matToFind == None:
return
findMaterial(matToFind)
if __name__ == '__main__':
main()
Correct me if I’m wrong, but doesn’t that do the same thing as the ‘Select’ button under the material indices on an object?
yes and no…
in object mode it selects the objects that use that material. you can;t do that in the standard GUI…
in edit mode you’re right that it does the same thing, but it offers you a list of the materials on the current object rather than having to fiddle with the “indeces” which is a particulartly nasty GUI in my opinion…(gladly addressed in 2.5!)
I have my own GUI that calls a bunch of my scripts (this is one of them) that gives me everything I need to use often in one compact panel…and as 2.49 dosen’t have “operators” I’ve had to duplicate some built in functionality to do that…
I thought as much.