Changing a material.Category in bulk.

T by theoryshaw on 13 Dec 2023, edited 16 Dec 2023 # +2 votes

Let's say you have (100) IfcMaterials with the Category = Foo. If you want to change the Category of all these instances to Bar, can you do this in bulk with BB?

S by steverugi on 16 Dec 2023, edited 16 Dec 2023 #

@SigmaDimensions said:

You can run this script:

import blenderbim.tool as tool

import blenderbim.core.material as core

for material in tool.Ifc.get().by_type("IfcMaterial"):

if "Foo" in material.Category:

    tool.Ifc.run("material.edit_material", material=material, attributes={"Category": "Bar"})

core.load_materials(tool.Material, "IfcMaterial")

my python knowledge is very basic and ChatGPT wasn't helpful

on my machine it returns an error


Python: Traceback (most recent call last):  

  File "\Text", line 6, in <module>  

TypeError: argument of type 'NoneType' is not iterable

do I have to add something to the script? in the test model I set the material Foo to 2 elements, thanks

S by SigmaDimensions on 16 Dec 2023 # +2 votes

You can run this script:


import blenderbim.tool as tool

import blenderbim.core.material as core




for material in tool.Ifc.get().by_type("IfcMaterial"):

    if "Foo" in material.Category:

        tool.Ifc.run("material.edit_material", material=material, attributes={"Category": "Bar"})


core.load_materials(tool.Material, "IfcMaterial")

T by theoryshaw on 16 Dec 2023, edited 16 Dec 2023 #

try this...


import blenderbim.tool as tool

import blenderbim.core.material as core


materials = tool.Ifc.get().by_type("IfcMaterial")


for material in materials:

    if material.Category == "Foo":

        tool.Ifc.run("material.edit_material", material=material, attributes={"Category": "Bar"})


core.load_materials(tool.Material, "IfcMaterial")

S by steverugi on 16 Dec 2023, edited 16 Dec 2023 #

@theoryshaw said:

try this...

import blenderbim.tool as tool

import blenderbim.core.material as core

materials = tool.Ifc.get().by_type("IfcMaterial")

for material in materials:

if material.Category == "Foo":

    tool.Ifc.run("material.edit_material", material=material, attributes={"Category": "Bar"})

core.load_materials(tool.Material, "IfcMaterial")

wow, that was quick :D

it worked out just fine, thanks a bunch

EDIT

the first script was correct but I used 'Foo' for material name, not Category, my bad

S by SigmaDimensions on 16 Dec 2023 #

@steverugi

do I have to add something to the script? in the test model I set the material Foo to 2 elements, thanks

Were you adding a Blender material to multiple objects? I think you don't have any IfcMaterial entities, so the loop isn't working.

In your test, no need for the material to be assigned to an object - you just need one or more IfcMaterial, with category="Foo". The material name can be whatever you want.

We can add a or [] to the for loop to avoid errors when there are no ifc materials in the current file, but then the script won't do anything, making it pointless :D Sometimes errors are good!


for material in tool.Ifc.get().by_type("IfcMaterial") or []:

S by steverugi on 16 Dec 2023 #

@SigmaDimensions said:

@steverugi

do I have to add something to the script? in the test model I set the material Foo to 2 elements, thanks

Were you adding a Blender material to multiple objects? I think you don't have any IfcMaterial entities, so the loop isn't working.

In your test, no need for the material to be assigned to an object - you just need one or more IfcMaterial, with category="Foo". The material name can be whatever you want.

We can add a or [] to the for loop to avoid errors when there are no ifc materials in the current file, but then the script won't do anything, making it pointless :D Sometimes errors are good!

for material in tool.Ifc.get().by_type("IfcMaterial") or []:

Yes, sorry I mistakenly used 'Foo' for the Name not the Category, your script is working OK, sorry!