Can I give existing models more polygons?

Question: Is there a way to add more polygons so that curved surfaces etc, are as rounded as they can be? (I do not care much about the file size it will be unless it’s in the gigabytes but I will try to simplify that later).

Background info:
I’m a beginner and I would like to know if I can transform other models to have smoother surfaces because of the resin printing I intend to do with them.

By default some kind of smoothing seems to be on in Sketchup and when I export it as STL it shows it’s true polygon count and it’s not desirable (but it needs to retain the outer edges!)
The resin printers will show everything especially the scale that I’m working on.

Thank you in advance!

There are extensions that can further sub divide surfaces to give them a smoother appearance. Thom Thom’s SubD from the Extension Warehouse would be the first one I would look at.

Not desirable how? Note that all surfaces will be triangulated in the .stl although they may not be in SketchUp. The .stl will generally have more faces than the .skp file.

Keep in mind that SketchUp doesn’t do well with very short edges and tiny faces. Working at a larger scale is often useful to avoid the tiny face issue. When I model for 3D printing I do so with Units set to Meters. I enter my dimensions (millimeters or inches) as if they were meters. The .stl file gets exported from SketchUp at meters and imported into the slicer using millimeters or inches as appropriate. If I have to start from an existing .stl it gets imported with units set to meters.

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Thank you for replying. I will google that tool after this.
I hope I’m doing this screenshot right with CTRL-V otherwise I’ll edit the message.

All those edgy surfaces are going to show, it needs to be completely smooth.

This Sketchup model came out so broken that it can’t be printed but that is a problem for another question. In Sketchup it looks good, I will try to export in other formats as well, later.

With a model as complex as that it’ll take some time but SubD will definitely help. Make sure you also take some time to actually learn how to use SketchUp properly. Start at

That is probably due to importing the original file at the real world units and the tiny faces issue. As I wrote previously, import with units set to Meters in the Import Options panel.

Also you need to make sure face orientation is correct. The back faces need to be oriented toward the print media and front faces toward air.

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Here’s an example of what I’m talking about regarding working in meters. Here’s my SketchUp model with hidden geometry exposed:

In the slicer it looks like this:

Note the dimensions in both of those screen shots.

And here’s a photo of the printed thing. Straight off the printer. Not cleaned up or anything. Shot with my phone after a pot of coffee.

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Thank you that does not look good indeed. It looks like it literally picked up all the designed parts without making them as a whole.

Here you can see how I’ve painstakinly transformed a Solidworks project from someone and had to get rid of all the inside parts and cavities because resin cannot have any cavities without holes to drain them!

This will give you a little bit of the idea what I can do.
I watched a video of Sketchup and I was motivated by the way to design but an hour later I also found an advertisment in my phone, somehow that Sketchup seemed to be notirious for having issues exporting to files to be printed.

I hope that it is just the measurement and the other thing you mentioned and how it can be fixed easily from other designers

Thanks again!!
Uploading: M249 camo LMG (3).jpg…

What doesn’t look good?

That isn’t actually true. Some users report difficulties but when looking at their models, the problems have always been due to the user not knowing how to use the tools properly.

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-I thought it was not printed well but it’s probably large layers and I almost don’t do FDM so for a sec I thought it was a bad print.

-That is indeed how I was glad to have read your answer first before I discovered that feed on my phone. I hope I can learn how to fix these things in existing models because if that can’t be done easily.

It could be a very painful way to design something and not go back and fix it. Anyway, I need to learn the basics first and try to move away from meshmixing more and work towards some more advanced programs.

I’ve been working my way through a lot of programs but in the end they were too steep for me to continue due to lack of time I can put aside for it.
Google said that this was quite user friendly and I was able to use much of the GUI with my mouse buttons without having to look everything up, so that’s a good thing for me already.

That thing is an FDM print done by a friend. I’m sure it’s not the highest resolution printer on the market. My point, though, was to show how smooth the curved surfaces are. The small faces don’t show in the 3D print.

Again, the first thing to do is learn how to use SketchUp’s tools correctly. There’s no point diving in on some incredibly complex model like you’ve shown if you don’t know what you’re doing in the first place. You’ll just be wasting a lot of time and making yourself frustrated.

With any application time you invest in learning to use it on the front end will be repaid many times over in time saved later.

SketchUp is very user friendly but it doesn’t mean you should just dive in and start modeling without understanding how to use the tools right.

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Sorry haven’t figured out how to quote properly. Usually I go to Facebook or something :slight_smile:

I think those faces are probably small enough already but in my model it’s pretty bad (imo) and to be honest a lot of stuff is made this way, so I find myself smoothing out a lot but some models are made different or bad, I don’t know this.

But when I smooth them the outer edges deform it into something alien like and other times I lose some of the edges but it is doable in the end.

I’m hoping to make stuff in SketchUp and prevent this beforehand. So, it’s very nice to know from you that this is possible. And I think most programs are able to prevent it, but only sculpters in generally (ZBrush etc) use enough polygons because they’re making miniatures for 3D resin printing for example.

For games and visual it is very common to stay low or very low poly and let the textures and GPU’s do the job.

I will try to YouTube some teacher who is implementing the focus of this ‘right way’ of creating things in SketchUp!

I was afraid of this… SubD is destroying the part in the process
there needs to be some option to turn ‘smooth edges’ on/off in order for this to have a chance of working.

So it will have to be something what you did in that model to keep the facetting from showing up in the print.
(also did not find the smooth slider, because I need to see the model as it is and not auto-smoothed like default in Blender)

This all goes back to what I told you several times already. You need to learn how to use SketchUp properly. You’re just diving in without any real clue of how to use the tools correctly. If you aren’t going to take the time to learn the basic tools there’s really nothing we can do for you.

Because it is not my model, I’m trying to see how much this program can do with this existing model. Googling all the options before I ask and taking the time to do the steps you told me getting SubD etc.

Quote: “So it will have to be something what you did in that model to keep the facetting from showing up in the print.” meaning that I already tried to make you understand that I understand myself that it has to be done upfront in the sketching but I don’t know SubD so I tried it first…

Just to hop in and back up @DaveR here… Even if you are using existing geometry, you STILL need to spend time learning to use the tool. In fact, some aspects of working with existing geometry are are more difficult than modeling from scratch.

If you want to put the time in, learn the basics at

Learn how to use the tools in SketchUp, then come back and start working with existing geometry. Until you learn the basics, something like fixing an imported mesh like this will be out of your reach. As much as the forum here loves helping people out, you will find the users are much more likely to work with you if they see you are trying to learn the basics… crawl before you run sort of thing…


Thanks I figured that out but maybe I wasn’t clear enough saying it. It is like some designers I talked to, although a lot of models I adjust and prepare in the slicer are very comlex and intricate.

Still I want to be able to learn how do to better than to adjust primitives that I summon and meshmix something out of that.
I had to know some things before I would start with Sketchup, that is why I went a little ahead past the basics so that I wouldn’t invest tons of time ony getting to know that it’s not the right program for me.

I hope you guys understand.
Thanks for your precious time and explanations!

I will continue to watch these tutorials online :slight_smile:
Kind regards.