I am doing a 3D model of a chapel in Rhino and I want to generate some plans with Revit, but I am getting a strange error during the import. This is what I am doing:
1- I save my model in a 3DM file (File 1). As you can see, the chapel is made by different solids: an arch, a vault, two pilasters and a cornice.
2- I open a new metric generic model family in Revit.
3- I start Rhino.Inside.Revit plugin.
4- From the panel of Rhino.Inside.Revit I import the 3DM file.
5- To my surprise, it imports perfectly all the solids EXCEPT the arch, that is missing (File 2).
So, what I tried is to generate a new 3DM file that contains only the arch (File 3). If I repeat the process, in the step 5 what I get is the following error:
Update 1: I need Revit to maintain two things from my Rhino file:
1- The NURBS geometry.
2- The elements classification. In Rhino each solid is inside a layer, for example, the pilasters are in a layer called “Chapel - Pilaster”. In Revit, I need that layers to be converted into subcategories, so I can change the visualization parameters of each element independently.
Rhino Document Tolerance [Units] has an affect on the import, you can try lowering that and importing.
You can clean up the geometry to get it revit compatible. The direct shape geometry importer will show you the locations of incompatibility and try to import the best it can.
You can determine what you are really needing to show in revit and create a lower res version that isn’t as detailed but accomplishes the documentation that you require.
Hi, Japhy. Thank you for your proposals. I’ve tried what I think is the easiest solution: change the document tolerance. I’ve changed it from 0.01 to 0.001, but I still get the same error. Before trying the other options you proposed me, I would like to ask you a couple of questions:
1- What is the difference between importing the 3DM from the Rhino.Inside bar option and importing via Directshape module with Grasshopper?
Because I am using the import option in the Rhino.Inside bar, but I see that you opened the 3DM file with Rhino inside Revit, and then, with Grasshopper, imported the solids with the module Add Geometry Directshape.
Even though the solid arch didn’t appear, the other solids (vault, pilasters and cornice) yes. I didn’t know that they also have geometry problems, but the fact is that Revit imports those solids (apparently) well, and I can cut them and generate my plans. So my aim is fulfilled anyways.
That is why I am asking you what’s the difference between the two processes, because with mine I get nearly all the solids, even with those geometry problems you discovered.
2- What is a smooth solid?
I didn’t mentioned it in my original post, but I will do it now: I need Revit to maintain the NURBS geometry from Rhino.
From the Rhino.Inside.Revit guide (Rhino to Revit) I read the following:
DirectShapes created from smooth NURBS surfaces in Rhino may be imported as smooth solid or converted to a mesh by Revit. If the NURBS is converted to a mesh, that is a symptom that the NURBS geometry was rejected by Revit. There are many reasons for this, but very often this problem can be fixed in Rhino.
All my solids were created in Rhino and they all are “closed solid polysurfaces”, so I don’t know why Revit changes my NURBS arch into a mesh with your import process.
Update: As I read in the same guide “DirectShapes cannot be placed in subcategories” so I think this option is not useful to me because I need to have each solid into a subcategory.
But I can draw that profile in Revit and, for example, make an extrusion, and Revit can work well with that geometry. So I don’t know why it has problems with the tangency between a line and an arch of my solid.
you will want to try going the other way as well, a lesser tolerance, especially when creating geometry. Revit doesn’t like edges less than 1 mm [1/32"]
[quote=“Edarq, post:4, topic:132782”]
1- What is the difference between importing the 3DM from the Rhino.Inside bar option and importing via Directshape module with Grasshopper?
[/quote] less control, it will try the same importers (first as a solid, sat, then mesh), but you won’t be able to apply parameters etc to the 3dm like you can a family or direct shape.
A closed polysurface, even one exported from Revit won’t necessarily go back into Revit. The surfaces and tolerances are going to different, with Revit being more particular and not oriented to a high degree of accuracy.
The issue like in the extrusion example you mention is the tangency during conversion isn’t going to know where to stop those very close edges, its best guess creates bad geometry (co-edge defining curve error above)
The general rule of 1mm edges is pretty straight forward, how it handles edge conditions, especially with non-planar surfaces isn’t as clear to describe except that intersections of two curved surfaces often create those small conditions that Revit has trouble with.
Hello again, Japhy.
Finally I solved the problem. The thing was that the curve that I used to create the solid of the arch was open! There was a 2mm gap. Even if Rhino considered the result as a closed polysurface, Revit did not. I’ve closed the gap, remade the solid and imported without problems into Revit.
In any case, I want to thank you for your comments, I’ve learned more things about Rhino.
See you,
