Grouping Items and File Size

Hi Fellow Sketchup Masters,

I have a question regarding file size and what the best options are for the fluidity of the model.
When importing items from the warehouse, say a chair, the chair has maybe 6 sub groups for individual components. Due to my large file size already, importing items like this can add too much to my model.

I was wondering if exploding all the groups into one group reduces the file size of the chair.

Also, i was wondering if say an object has multiple layers of groups, and each group within has a different layer. Is there a way to change every sub group to one overall layer without going into each group individually…

Thanks Frends

It probably won’t have a substantial influence on file size but you can see for your self by inserting the chair component into a blank file and saving it. Check the file size and then explode the groups inside the chair component and see what the difference is.

A more effective thing would be to edit the components and eliminate details that aren’t needed. Simplify the components before you add them to your project.

I tested this theory out,
Turns out exploding the sub groups into one group nearly triples the file size.

My other question is still out there for anyone to help with, regarding changing all sub groups into one layer, without going into every sub groups.

As for the layers, thing, you could open the parent component, select all the child groups or components and assign them to a common layer in one step. If these components you’re getting from the 3D Warehouse come with a bunch of layers, delete those layers and SketchUp will move the component/groups to Layer 0.

If you aren’t already doing it, the recommended process for using components from the Warehouse is download them into a separate file, check them out to make sure they are suitable, do any cleanup that might be required and only then insert the component into your project.

1 Like

Generally, using components and subcomponents brings the file size (as stored on your disk) down but the SketchUp performance depends directly on the faces and edges the application has to process. Components, especially when deeply nested (subcomponents within subcomponents within…) even somewhat increase the processing overhead, so when you tried exploding them, yes, file size bloats, but SketchUp itself might perform marginally faster.

1 Like

Expanding a bit on what @Anssi wrote, one of the strengths of components (and unmodified copies of groups) is that the actual collection of edges and faces defining the component are stored only once in the model. They are then transformed and presented on the view at each place you put an instance of the component. Typically the incremental data to place an instance is small compared to the edge and face data of the component definition. If you explode the components, each edge and face must be stored separately and the volume of data in the model jumps up - even though the count of displayed edges and faces is the same.

For display, each edge and face has to be transferred from the model database to the graphics system. So, the time to generate the display depends mainly on the number of edges and faces regardless of whether they came from components, groups, or were “loose” in the model. Rendering “loose” geometry requires one fewer stage of transformation (from the component definition to the model coordinates) so it may be slightly faster but the transformations are highly tuned to minimize this effect.


Thanks Guys,
that helps more than i could have expected.


SketchUp runs on geometry. A group or component is simply a grouping of geometry. Exploded, or loose geometry, is singular geometry. This geometry is harder to load because every time you adjust your view or reload your model, the program has to rebuild all the geometry. This is why the file size is larger. I have recently used the component/layer method, using components and layers to decrease file size and processed geometry. Using layers only shows the geometry/components you need, decreasing lag and making it easier to run the program. I strongly offer exploring these tips to decrease file size and lag. To answer your group question, the less groups/components created, the less unique geometry redrawn, reducing file size.