Capturing external shapes

I`m using rhino 6 for just a couple months now and I could use some help.

quick backstory: my company does wind tunnel testing for new buildings. So we receive the files from the client - usually heavy revit files - and then my job is to recreate that massive skyscraper into a small solid version that can be 3d printed and put into the wind tunnel for testing.

Im a professional solidworks design but since solidworks doest work very well with revit I`m using rhino as the “middle man”.

The thing is, the process we are using now is very time consuming and kind of clunky to be honest, and I can`t shake the feeling that rhino can do more than we are using it for (we are all beginners in rhino in my team).

I import the dwg file of the whole building (including interior parts) to rhino but for wind testing Im just concern with the overall shape of the exterior. The building usually has thousands of surfaces and polysurfaces, and even meshes sometimes, and they are not necessarily connected, which makes things harder. Ive been messing around with the drape command, and although it gets pretty close to what I`m looking for, unfortunately the surface it generates is way too irregular for me.

I wanna know from you guys if you know any command/feature in rhino that i might be missing. Or any workflow that would give me that exterior shape. Any help is welcome. Cheers

Saw this link: About Eddy

That seems to be a plug in for some wind flow simulations. Although interesting, that’s not exactly what I’m looking for, since the company already has that part of the process covered. I just really need a way to manage the revit file and export it as one solid body.

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Hello - see - that may, possibly, help your general workflow.


I worked as a architectural model builder and we did A LOT of this. There is no simple solution to skinning and shelling geometry that comes in from other software (or native Rhino geometry for that matter). Using Revit geometry as reference and modeling on top of it for 3D printing will give you the most control and accurate results. I’ve experimented with skinning models in programs like ZBrush with mixed, mostly terrible, results. The root of the problem is that workflows for BIM and rendering (no huge issues with open/intersecting geometry) are very different from that of 3D printing (requires closed manifold volumes that don’t intersect.) Unless the designer is modeling with the intent to 3D print, it is very unlikely that it’s geometry can be reused for 3D printing down the road.

The bright side is that you can get crazy fast at Rhino modeling by doing this all day every day.

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I see… I thought maybe because I’m new in rhino I could be missing some feature like the drape one.

But I agree, since most buildings are just simple extrusions the process can be pretty fast. I’m doing all the modelling in solidworks and it only gets tricky If the building is too complex and full of details, which doesn’t happen very often.

Must-know commands that help to extract and clean up building footprints:

CurveBoolean (my all-time fav command)
TestCrvSelfIntersection (shhhh, its a secret.)

I hope this helps!

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Might you do your CFD testing in Rhino/Grasshopper with with Butterfly and Openfoam?
The setup is easier with BlueCFD’s version of OpenFoam, as in Formula Translator.

By itself, OpenFoam is the single most user hostile piece of software I have ever encountered, but even I was able to get the test case going with Butterfly’s tools.

It appears that OpenFoam’s results were validated very similar to Fluent, which costs about an astounding $23k, a year, per seat. OpenFoam is free, as in free-beer, or free-kittens!

The gist of the thing: OpenFoam has been generally Linux-native, though a Windows version is by BlueCFD, which is installed first, and runs as Admistrator, waiting for jobs, which Rhino/Grasshopper provide with Grasshopper widgets and a python back end.

A big hat’s off also goes for the makers of BlueCFD who stepped in, and provided a sane alternative to Docker, by doing a native OpenFoam for Windows.

I’ve heard that is finally considering a native Windows version. If it works out, please put a post here, to drive another wooden spike into Docker’s undead heart.

Thanks Brenda, but Im just responsible for designing and prototyping. I dont run the simulations myself. I believe the guys here use fluent though.