Revit among architects is much more common these days, and it makes everyone’s job easier including 3D artists. However getting that revit model into 3dsmax is not always the most straight forward process, and finding the right workflow from Revit to 3dsmax can feel like searching for the Holy Grail. I’ve become quite familiar with this process and decided to post my experience with the various ways to get a .rvt file into a beautiful .max format.
When exporting to dwg from revit, it’s really straight forward. There are 2 flavors of dwg to export from Revit (Solids vs Polymesh), but they have been moved from the standard dwg export, to revits dwg export options under the Solids tab. For the most part, you can leave it at the default settings. Now, the advantage of dwg is that geometry comes in clean, poly counts are low and curves come in not too tessellated. Also, families from revit will come in as instanced geometry, which is really nice and keeps the file size down. One disadvantage is that that any links from the revit file get dropped. So if there are any mechanical, structural, or other revit linked files, they don’t get picked up upon export. So if you’re coordinating with an architect, it can be a pain on their end to open each of the linked files and export them out separately.
This for a while now has been the silver bullet when it comes to file interoperability, and Autodesk has worked really hard to get this one fool proof. For the most part, it is. The nice thing about fbx, is that any revit links will get picked up with the base .rvt file. It will also be mental ray ready, meaning if time was spent in revit to add materials and lights, they will come in with the model. There are 2 big disadvantages to fbx however. The tessellation on curved objects such as railings are incredibly bloated and very heavy in poly counts.
Since 3dsmax 2015 (I think) it’s actually possible to import or link a revit file straight into 3dsmax. This seems like the most obvious option, and actually is not a bad one. The advantages are that you don’t need revit to get your .rvt file into 3dsmax. Other than that, it has the same tessellation issues as fbx. Unfortunately just like dwg, it doesn’t have the other linked revit files that the architect may have. So in this instance, fbx is always better than rvt…for now.
Link or Import?
On the max side there are several ways to get your geometry into your scene that can give you different results. I will say linking almost always gives you more control on how to handle the geometry. To link in 3dsmax go to the top left jewel icon->Import->Link Revit/FBX/CAD.
There are several ways to link the geometry. Much of it depends on how the revit file was handled. For example if you know it’s textured correctly, then choosing “Combine by Revit Material” would be a good option. However if you chose that option, and there were no materials on the revit file, then the geometry will come in as 1 humongous mesh, and a pain to work with. Typically I choose “Do Not Combine Entities”, as this imports every revit family as a separate object just as it is in Revit.
When you link an .fbx file, a folder in the same location as the fbx is created and 3dsmax dumps all of the embedded texture maps relating to the Autodesk materials to that folder. I typically delete this folder, as I use my own material library. When you import a .rvt file, it will ask you which camera do you want to link. Currently 3dsmax will only let you choose 1 camera to link. This can be problematic if the architect has dozens of cameras in their revit file. After linking is complete, then I go back to the link manager and bind what I have in my scene so it will convert everything to editable meshes.
After going through all these, my favorite is dwg from revit. Mostly because curved objects are not overly tessellated and multiple objects come in as instances. This is only when I know that the revit file does not have any other revit links. Now if there are revit links, or I’m not too sure, my fool-proof method is fbx. The downside of course is with a large and bloated file. Also note that in the fbx format revit families are still instances. As soon as they come into 3dsmax world, every mullion, furniture, toilet stall is a copy, which makes files huge. To combat this I have a maxscript that finds identical geometry and converts them from copies to instances. You can download it here. With this script, I successfully got a 1.4GB max file down to 150MB. If anyone has other experiences or solutions feel free to share.