Revit (FBX) Pains

[trixian]

I'm working on a large model of a building site, and I have received the Revit files from the architects. Originally I used the "suite workflow" they included and sent the file directly to max 2013 from Revit. Problem was then that regardless of what options I selected, it always grouped objects by materials or type, even when choosing none.
After that I decided to do a manual FBX export. My new problem, other than a weird system of not all instances being instances, I had a relatively simple scene clocking in at 168 megs, but even more worrying, that it took 7 minutes to save (locally on my system SSD). It turns out that every object has a unique material, with a unique map, resulting in several thousands of materials and maps all illogically connected to various multisub materials, per object. (Like 930 materials for the 930 identical steel parts of a handrail).
I have tried the classic replace by assigning a material with an identical name and getting it to ask me if I should rename or replace, but not all names are the same, so this doesn't help much. Also AD materials update considerably slower than other materials in the SME using vray it seems.
Does anyone have any tips on how to handle this?

[pailhead]

I had this issue with an import from rhino. Not exactly sure which format it was, but it was a parametric model made with GH and it was performing poorly even though it wasnt so heavy. Turned out that every single object had it's own material. I think that at first i was trying to join these objects into a single mesh and it would just freeze max. If you do a UVW remove, you can remove the materials, if that is the main issue. I don't know anything about exporting from REVIT but i did get a model recently and it works relatively well. It doesnt have layers but all the materials are there and it seems to recognize instances.

[trixian]

Yes. Revit does not have layers, it has "family type" and other classes to distinguish objects. It also supports instances through export formats like FBX and DWG. The problem is that the instances are not all instances. For every model that was referenced in the main model, the instances are unique. So if a house is referenced in 5 times and placed at it's designated footprint, there will be 5 identical sets of instances, and selecting one, and doing the "select instances" command will only select the objects inside the one building, and none of the rest. But this is a minor problem when it comes to objects, as it is the material issue that is killing me. I need some way of making max assign one of the materials to all its instances, but max doesn't recognize that these materials are the same even though they are. It seems the only thing telling max about materials are their names. So if they have unique names, they are not instanced. Does anyone know of a script that can compare the parameters of the materials and condense them on those grounds?

[DanielBrew]

Does anyone know of a script that can compare the parameters of the materials and condense them on those grounds?

Sebastien Guimmara (groutcho) posted a script a thread on CG Talk a couple of months ago that does something like this. It only worked with standard materials originally but I've added support for VRay materials and it wouldn't be too difficult to make it work with Autodesk Materials as well.