Getting SketchUp to re-use the same geometry of a window or door when exporting as an .fbx

Hi there –

Hoping someone here can help me…been digging around for a solution to this for a while. I’m directing a project in which we’re re-creating buildings from a lost neighborhood in L.A. called Bunker Hill (see the project here:

The buildings we’re modeling in SketchUp almost always use the same windows over and over (on larger buildings, we’ll use the same window circa a 100 times) and so when we export a building as an .fbx it has a massive file size. If I export a building as an .fbx with only one window, the file size is often somewhere around 90% smaller.

So, is there a way to get SketchUp to recognize that it is THE SAME window with the SAME GEOMETRY so that when we export as an .fbx, the file size is smaller?

I apologize in advance if there is an obvious solution I’m missing.

And thanks in advance for any help!

are the windows components or just groups? not sure what is happening in the export process or if it would matter, but if the windows are components (meaning a single definition with instancing of that definition) it might be something the .fbx would also pass as a single reference.

It does look like FBX saves a unique copy for every one of the same component.

If you are going to use the model in Unity, for example, you could go via Collada. That does have the option to keep the component hierarchy. In a quick test exporting 10,000 boxes, FBX went up to 35 MB, and Collada was still at 71 KB.

Thanks @glennmstanton

They are components with the same definition, but still, the more I add, the larger the .fbx file gets.


That works!!! We are in fact, adding these models to Unity, so this works perfectly. Thanks SO much!

However, can I ask one more question, in case you know the answer to this as well?

About half of the windows filling up these huge file sizes are classified as Groups and not Components. And if they are not Components, .dae still saves a unique copy for every one of the same group.

Is there a way to make several objects all instances of the same Componentin SketchUp? In other words, if I click on one window in a model that we use 100 times and make it a Component (and name it “Window_1,” for instance), how do I then click on the other 99 windows and make them each an instance of the Component “Window_1”? Any ideas?

It could be a useful feature to allow you to replace selected groups with a given component. I will pass that on as an idea to the team.

Meanwhile, there is a clumsy way to do what you want, without too much pain.

Select the first group carefully, type G, give the Component a sensible name.

One by one, for the other groups of the same kind, select the group, type G, hit Return without caring what the name is. Pretty quickly you can make a ton of components.

Select all of those new components in the scene, and in the Components panel right-click on the sensibly named one. Choose Replace Selected. Go to Window/Model Info/Statistics, and Purge Unused.

That will delete all of the temporary components, which a moment ago you replaced with the sensibly named one.

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Thomthom’s selection toys will do it for you.


We should hire @thomthom. Oh wait, we did…

He could implement it as a built in feature.


Yes. This is a great workaround @colin. Thanks so much, again. You’re a gem of a human being. I’ve been trying to Google my way through this problem for a while now and you solved it in a matter of hours!

Hey @Box - Thanks. I installed @thomthom Selection Toys and it looks like it will allow me to select all the groups in a given context, but will it also allow me to automatically convert each of those groups into instances of an existing Component? Unless I’m missing something…

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When you select one of the groups you’re wanting to convert, does it say in the entity info box that there are multiple copies of that group In the model?

If so, select one of those instances and then…

  • Right-click > group copies > select all
    then once you have them all selected
  • Right-click > group copies > convert into components


(If you are having a hard time reading the gif,
Right-Click the gif > open image in new tab)

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Wow! Just donated $100 to @thomthom - with your instructions and his Selection Toys I was able to do EXACTLY what I needed, saving me hours upon hours of work.

Thanks to you and everyone (@thomthom, @colin, @Box, @glennmstanton) who helped me solve this problem over the lest 24 hours.



Glad you got it resolved.

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