MaterialAsset.IsUsed wrong?

[tobias_wiesendanger]

I've got a empty part which has two materials and both are not deletable. If I look with the api the Propert IsUsed is in fact set to true. Is there any way to check by what? I think I looked everywhere and cannot figure out where this could be used and how to delete it.

[WCrihfield]

Hi @tobias_wiesendanger.  Is it a sheet metal part, or a regular part?  I don't think you can delete a material while that material is the 'active' one for the part document, even if it has not been applied to anything within the document, due to there not being any model to apply it to.  Also, since materials contain data about the material, its appearance, and its physical attributes, I believe that if there is an appearance in the documents appearances that belongs to a material, you will not be able to delete the material from the document materials, before you delete the associated appearance from the document appearances.  Try purging the appearances thoroughly, before trying to purge the materials.  Have you tried using the Purge tool on the Manage tab > Styles and Standards panel for this task?

I went through these same struggles myself at one point, and likely so did the majority of others.  It can be pretty confusing/difficult trying to effectively get rid of appearances, materials, and especially drawing styles out of documents, because it can be difficult figuring out where they are being used or by what.  In sheet metal parts, you have to consider your sheet metal rules contained in the document, which reference materials.  In weldment type assemblies, even though they don't technically contain materials, they have default material for welds, if you create any.  In drawings, there are title blocks, borders, sketch symbols, default styles, and styles that reference other styles, and the list goes on.

[tobias_wiesendanger]

I thought I know pretty well how the usage and deletion of appearances and materials works. In this case there are two materials and two appearances. One Material and one appearance are in fact in use, because you need to have a material assigned. Im not trying to delete those two. There are two more that shouldnt be in use, but they are. I dont know by what. It is a sheet metal part.

[WCrihfield]

OK.  Then this may be due to sheet metal styles that may exist as local copies within the document.  To check on this, open the Style and Standard Editor dialog, then set the drop-down in the upper right to 'Local Styles' instead of 'All Styles', then fully expand everything under the 'Sheet Metal Rule' category in the left list.  If there are more than one listed, you may need to get rid of the other ones that are not being used.  Then try to purge those appearances and materials again.

[tobias_wiesendanger]

There is only one sheet metal rule and that one is using the correct material that I would like to keep. I already checked that. This shouldnt be the problem. The idea is to keep Generic as a material and default as a appearance.

[WCrihfield]

When I opened your part, a dialog popped up about 'derived' stuff that it could not seem to find, and that it was apparently still linked to.  There was no visible geometry, even though it has one item in the model tree named "Blech.ipt".  There was just the one material ("Generic"), and just the one appearance ("Default"), and no sheet metal styles, because it was a regular part, not a sheet metal part, and did not contain any of the default sheet metal parameters.  I'm using Inventor 2022.3.2, so if your part was made in 2023 it might not be opening correctly on my end.  But if the part is derived, and remaining linked to another part, the extra material and appearance may exist in the other linked document, and that may be why you can't get rid of it from within this document.

[tobias_wiesendanger]

It was last openend and save in inventor 2023. So what you are seeing is this future / any cad feature that allows you to open a newer file and it shows as a linked / referenced file. There is no link and no geometry in it.