Hi Kevin,

> Is the "Manifold Solid B-Rep Object Entity (Type 186)" in IGES not used?

Historically it is just not as common as individual surfaces.


> or is it a weaker implementation as in STEP?

I don't really know off the top of my head exactly how IGES entity 186 compares to object structures in STEP. But I kind of think they are generally similar in idea though.


> or does it not even describe the true solid?

IGES entity 186 I believe does describe a true solid.

- Michael

Great!

I love reading this forum, I've learnt so much from your excellent technical advise to situations all of us run into (shelling errors, fillet problems)
And the fact that this is software independent means the advise applies to many different modeling packages and situations.
So valuable!