Huge fbx model on export



I am starting with Sketchup, actually I am no modeler but programmer.
I imported a icf file into Sketchup (with a plugin), then I export as fbx.

Importing in Unity, I get like 8.5M vertices and 9000 batches. I managed to lower the batches to 900 via a script.

But this is for hololens and 8.5M vertices will never do. The model is actually a residential building without much complexity. I just don’t understand how it adds up to so much.

Is there something I could be missing? Or at least something I could try to lower the polygon/vertex count?

I was thinking to remove the inside of the building but I see videos of complex buildings and setups running just fine in Unity so how come my model gets so big out of sketchup?
If I purchase the pro version, is it going to fix that issue?

Thanks already.


Did you look in SketchUp what the Window menu>Model Info>Statistics dialog has to say? Check the “Show nested components” box and you should now see how many edges and faces your model actually has.

You imported it from an IFC file. The quality of the original file is crucial here. What BIM application does it come from?

Exporting to FBX may even add to the count as Sketchup supports polyfaces but many export formats are triangulated.



Thanks for those, I’m all fresh in Sketchup so I simply do not know what and where to look.
I will have access to the file again on Monday and will look at what you say.

The ifc file comes from the customer so I do not know what did it but we were once given a cad file so I would say they use ArchiCAD.

Thanks again.


So looking at the Statistics, I see 1.125M edges, sounds like a lot doesn’t it?
I tried exporting a collada file, ends up at 235mb.

I just don’t understand how a building model can generate so many data…


Could be lots of reasons. If you make the 3d models yourself, you decide how much detail you put into it. When using external libraries you can get into all kinds of trouble because they have a different goal in mind; just to make that single element look as nice as possible.
I have seen libraries where 1 element (for instance a piece of furniture) contains as much faces and edges as my complete design for the building model. At that moment its digging into all the different elements and manually delete what you don’t need or replace it by your own models.


Thanks. Fact is we cannot afford to manually start working the items…

Would there be a decimating tool on Sketchup?


Not that I know of.

Edit: it is / was for a long time - sort of a holy grail in 3d gfx. Reduce a 3d model in size while not destroying the overall characteristics / look&feel. I hope someone else on this forum could say more about this.


Yes, it is a lot, especially if you plan to use the model in a game. As MaxB says, the culprit might be a 3D plant or an item of furniture (again, perhaps imported into ArchiCad from some other application). Things like rounded edges or plant or car parts can have a zillion infinitesimally small faces that just sit there taking up file space and system resources while looking just the same as they would without all the overmodelling. Pure Archicad GDL objects tend to be small and simple as they are created by painstakingly writing a script in the GDL language.