How can I record face name in STEP?


I am writing plug-ins for Rhino, using the Rhino SDK.
I want to set a name to each B-rep face ,and hope these names will be recorded in STEP file.

For example,
If I set a name “Face1” to B-rep face.
Than I want to “Face1” will be recorded in STEP file as shown below.

It is not possible to set names on parts of a polysurface (BRep). So, unless you write the STEP file yourself this is not going to work. You can only name the complete BRep (in your case ‘brep_1’).

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@boy10322, why do you need to do this? What problem does this solve for you?

– Dale

I want to save some information for each face.
I hope that next time I import this STEP to Rhino or another CAD system ,than I can use these information to do something.

I still don’t understand what you would do with data. What application reads this type of information from a STEP file. How would you access it? What would you do with it?

Rhino does have custom data on Brep faces that can be written to a STEP file. Before I report a wish item for this, I need to know why it is needed and what problem is solves for you.

– Dale

Dear all,
I have a similar situation.
I want to mark specific faces in a Brep model, and export to another CAD platform via a CAD file.
After I import this file, the platform still can show these faces I have marked.
So, if I mark faces in a CAD file is a good way or not?


Hi @Marshall,

This isn’t all that difficult.

What is difficult is: 1.) determining what files formats, other than 3dm, would support this, 2.) getting other applications that support these formats to read this data, and 3.) being able to access the data from another application via API or something else.

I’m not very optimistic about 2.) and 3.).

– Dale