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View Full Version : Uffffff... Another buggy feature? 3D solids export



A3D
2006-02-19, 07:56 PM
Short story:
I have to do a 3D model and I choose Revit of course . Everything works almost fine.
I have to hand over the 3D model as DWG solids model.

Problem:
Now, when I try to slice a solid in AutoCAD I get "Inconsistent face-body relationships" on 90% of cases.
Joining 2 or more solids results in strange looking solids (see image)

Question:
Anyone has stumbled across this?

Thanks

A3D
2006-02-19, 08:17 PM
I managed to pinpoint the problem:
The solids corresponding to walls will be corrupted when there is a floor going to the core of the wall.
Looks like Revit fails to produce an accurate solid on this subtraction operation.
However, if there are only window/door openings, the results are valid solids.

mmodernc
2006-02-19, 08:36 PM
when is a solid a solid - seem like hollow boxes to me

A3D
2006-02-19, 08:51 PM
I'm not quite sure I understand you.
The attached image shows windows openings in a wall.
When I say solid, I mean the AutoCAD 3D solid type of entity. A valid solid in AutoCAD never displays those diagonals after a hide command.

Steve_Stafford
2006-02-20, 02:16 AM
Just to be clear, are you choosing the ACIS Solids option or the Polymesh option when you export to dwg?

A3D
2006-02-20, 08:23 AM
Ya, sure...
Otherwise I wouldn't be able to slice or to do solid boolean operation in AutoCAD ;)
Last night I also noticed that a few other categories don't export properly (the railings for example).

cwentworth
2006-03-23, 11:52 PM
I make solid models for architects. What your looking at is polygons. On "solid" models the data is turned into polygons which is just a collection of triangles. That’s what you are seeing. Revit will not output a real solid object. It only outputs mesh objects. Even the acis dwg output is just a collection of meshes. To get a model from the Revit data you need to output a vrml file from AutoCAD. Then bring it into a mesh editor like Magics to cut it up and edit it. You could output an stl from AutoCAD if you can join it into one object but I doubt you will be successful at that unless it's a real simple object. If you like you could send me the file and I’d be happy to look at it for you.

Chris
3DRP