Changing a material.Category in bulk.

theoryshaw

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?

SigmaDimensions

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")

steverugi

@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

theoryshaw

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")

steverugi

@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

SigmaDimensions

@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 []:

steverugi

@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!