[Question] Why do closed Composite Parts lose their original parts colors?

n_schoemaeker

Hi all,

when creating a closed Composite Part out of several parts in a Part Studio, the Composite Part becomes gray (or some other arbitrary color) instead of keeping the original parts colors. It forces us to alter individual faces' appearance and it becomes very tedious very fast for non-trivial parts.

My question is: why is that so and can it be fixed by OnShape devs? When we don't check the "closed" checkbox, we do have a Composite Part that's the right colors (but then all the individual parts are not deleted).

Anything obvious I am missing?

Thanks in advance

_anton

Yeah, an open composite is a less aggressive grouping that lets you keep individual part properties. The difference is that it doesn't "consume" the underlying parts. Performance, among other things, motivated closed composites: when you, say, import it into an assembly, you're only moving around the composite's own properties, not those of the ten thousand parts it contains. Part appearance is among the data eaten by the closed composite. (You do keep face colors, though.)

One could picture a "clopen" composite that somehow partially consumes its parts, but that easily gets into the complicated and non-intuitive weeds.

Can you work with an open composite?

n_schoemaeker

@_anton thanks for your answer.

I completely understand the fact that a closed composite part consumes its individual parts, and you lose some information, this is why it gets a performance boost.

What I don't get is why it cannot keep the faces color: when I create a closed composite part, it becomes gray and even the surface lose their color.

See example here: https://cad.onshape.com/documents/07f6b264870972fb60fe6dd0/w/5d50749348e927a83cfa04be/e/f11cd41d2df082bd7238407b?configuration=Closed_=false&renderMode=0&uiState=61b8678b2f0ab91c02d5bf6b

I have created three parts, I have specifically added some appearance color to each of them, and then make a Composite Part.

You have a configuration checkbox at the top to set if the composite part is closed or not.

When it is *not* closed, the colors remain okay, but when it is closed, the composite part becomes gray.

"Can you work with an open composite?" -> this is what I do now, but performance wise, I wish I could work with Closed ones

_anton

Right, that's expected. In that doc, the parts all have an assigned color, which is eaten by the closed composite. It's a have-your-cake-or-eat-it sort of situation; carting around more info is less performant.

That said, face color overrides (under the Appearances panel) are different and can be used as a workaround. See here for more info: https://cad.onshape.com/help/Content/appearance_editor.htm?cshid=appearance_face#Customiz