Pipes / ducts / etc export using system material not actual material

[Moult]

If I click on a pipe and check its instance properties, I see a "Material" property with something like "PVC" or "Copper" set as a material. These are legit materials and found in the Materials browser / manager.

However, let's say these pipes are part of a system called "SEWER". If "SEWER" as a Pipe System has a material set (i.e. not "By Category"). Then, that material will be used, not the actual material of the pipes / ducts / etc.

How do I get the pipe to export using its actual material, not the system material?

This in practice has multiple problems, firstly a lot of MEP users model using the system material as something like "SEWER" which means pipes end up having materials named after systems, like "SEWER", "HOT WATER", etc instead of "PVC" or "Copper". Also, some systems may have pipes with different materials in them (like portions being PVC, other pipes being HDPE).

[AngelVelezSosa]

They work that way because that was the overwhelming demand that we use the system material and not the actual material. If there is use for both, that could be an option. I'll look in the morning to see of I can find evidence of my claim.

[Moult]

Yeah probably because back in the day people got confused by styles (colors) and materials and wanted their color coded pipes and ducts to show up with the "right" color in IFC viewers. Its unfortunately semantically wrong: a pipe is made out of copper, not "hot water supply".

I think if you used the system material as the style, but the real material as the material, you can visually satisfy the old crowd and semantically deliver the correct data.

Probably another factor is that older or lower quality IFC viewers had no way of showing systems, whereas that has changed now.

What do you think? Time to revisit this with an emphasis on correct data?

[CyrilWaechter]

@AngelVelezSosa I opened #112 long time ago and as @Moult guessed how it is described was mainly result of a lack of knowledge about IFC. If I knew it was possible to get both (pipe actual material and system style) I would have written the issue this way. So I agree with @Moult it is far better to correct IFC export the way IFC is intended to be used and inform users and viewers developers about it rather than fixing in the wrong way.