Hi @KenFarley ,
I don't think this addresses the question, which is how to control the material or its density via a relation.
@LH_10601291 ,
The density parameter for a material is PTC_MASS_DENSITY. you can use this in relations as PTC_MASS_DENSITY:MTRL_## where ## is the feature id of that material in the model. I believe using a relation to set the density will affect only the use of the material in the model where it is set and will not change the default values assigned in the material library.
In the Relations window, you can view the local parameters and right click on your desired parameter > Insert to Relations to add it into the Relations field above and it will automatically add the :MTRL_## needed.
