Radius segment limitations

How can I bypass the radius segment limitations in SU 2021?
I get this warning when using the radius tool in situations that, it seemed to me I would not in previous versions of SU: (Example is .10" diameter using the radius tool set at 24 segments)

You are bumping into the lower size limit of geometry that SketchUp can produce with each tiny segment of the curve. This limit has not changed with any update of SU that I know of. Geometry that small can exist but sometimes cannot be created by some tools. Solutions are:

  1. Reduce the number of segments until each segment is large enough to be created. Meh.

  2. Scale up your curve so that the size will support the number of segments you want. You can then scale it back down.

  3. Best of both worlds, use the Dave Method which is simply making the geometry you want to edit into a component, placing a copy of the component somewhere off to the side of your model, scaling up that second instance of the component by an appropriate amount, say x100 or x1000 depending, then open the second scaled instance for editing and make whatever geometry you like. Anything you make in the larger scaled instance will be reflected in the original and you can just delete the larger one when you are done, or keep it for future editing.

A good rule of thumb when not using the “dave method” is to not generate edge segments shorter than abour 1 mm.

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I appreciate the advice. The scaling workarounds are sound methods. I also use Fredo’s Curivizard tool to smooth (subdivide) curves on occasion.
The problem I run into is a time issue. I use SU for all my 3D projects & deadlines are tight so having to do a multi step workaround is not optimal.
Just to be clear about my reference to the segment threshold of the radius tool and how it has changed or become restricted to a larger size cutoff, See the attached screenshots:
Example1 is done in SU 2015 (yes I still have it installed): .1" diameter, .05" radius @ 24 segments, radius tool does that no problem.
Example2 is done in SU 2021. .1" diameter, .05" radius @ 24 segments and it is a no-go.

Not sure what benefit having tools that in 2021 are lower resolution than they were 6 years ago is?
Sketchup certainly has the capability, with the native tools, (per my examples) to deal with segments that are much smaller than is currently being deployed. Does anyone know why the segment threshold for, (in this case the radius tool) is so much lower than it was just a few SU iterations ago?

What has changed is that newest versions of SketchUp issue a warning.

This change didn’t happen with 2021. It was made a few versions back. The reason for it is that more people are using SketchUp to model for 3D printing which requires water tight objects: no holes in surfaces. This segment limitation was put in to help users avoid creating situations where they run into the “tiny face” issue.

Are you modeling for 3D printing?

I run into the small-geometry problem quite frequently in my modeling efforts (which are mechanical design subjects). The Dave method is very helpful and costs almost no extra time when viewed over even the short-term life of modeling an object.

  1. Create the beginnings of the object at 1:1 scale, and make that starting geometry into a component.
  2. Copy a new instance of the component off to the side or up or down etc.
  3. Scale that copy up by 100X or 1000X.
  4. Do most or all of your remaining work on the object within the context of that large-scale instance. The modifications applied to the large-scale instance will automagically apply to the original 1:1 instance of the component.
  5. When the component model is essentially complete, close the context and delete that instance.

The time to execute steps 2, 3, and 5 - which require only a few seconds - is total noise in the overall process of creating just about any object. I sometimes switch between editing the large-scale instance and looking at the 1:1 scale objects for references etc., but even such examples of switching context are pretty quick. And there is no faster alternative with SketchUp, which does not handle tiny geometry well, and presumably never will handle it much better.

Is that method relaible though, or will it risk corrpting some of the geometry when it is squashed back down?

If it is indeed robust and error-free, then why can’t sketchup model at smaller increments?
I dont really understand it - if it can calculate things to that size and draw them using the Dave Method, then why can’t we model to that size to begin with? Is it graphics-related?
Is there no way then to ask the software to calcualte to extra decimal places, or to use an “extra precision” option?

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Maybe that little warning message that comes up could have a box saying “Click here to learn about the Dave Method”



That’s interesting. I have been using SketchUp for a long time too and I remember the pop up being implemented, but I didn’t realize the threshold had actually changed.
When I’m modeling for 3D printing with consistently tiny geometry I have adopted the common practice of setting the model units to meters and modeling as if they are MM. Units are not specific if you are exporting as .stl anyway. For small discrete objects I am able to work in scaled metric and I find this avoids the problem entirely.

For architectural scale design, where I work in imperial, I mostly find that anything size limited is too small to see/render anyway. On the rare occasions that I bump into the limit I find the Dave method to be the quickest fix.

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It is very reliable in my multi-year experience using the Dave method with 1500+ mechanical components. I use a 100X scale factor for the large component instances. This still runs into too-small geometry sometimes. Therefore, I frequently Save the model to trigger the validity-check function which will reveal problems. Any problems that are “repaired” (i.e., actually made worse) by the validity-check will require manual fixing by relocating some endpoints, and/or simplifying localized geometry a bit. Then I Save again. If the save succeeds without discovering (causing) problems, then the model should be fine.

Every once in a great while, something that was cleanly Saved in the past will trigger validity-check failures during a subsequent Save. I’m not sure why that happens.

We will probably never know.

Thanks for the explanation as to why segment size is limited.
I am pretty sure the “change” occurred in SU 2017? It’s something that has been bugging me for a while. I ended up using SU 2016 till about 2018 in part because of that.
I do not do stuff for 3D printing. I design store fixtures. A-lot of my work goes directly to engineering so accuracy is pretty important for what I do. I also have to model client products (Keurig machines for example) so am often working with fairly high poly counts.
I had a suspicion that the segment threshold was throttled to “help” folks out, but, in my opinion, as a professional, experienced SU user, it makes absolutely no sense. For a casual user who might need guardrails to prevent self imposed problems, sure, but for a pro user, working in an environment with tight timelines, it’s a hinderance.
I use a bunch of plugins that really expand the capabilities of SU and frankly make it a much more powerful program than it is out of the box. Reducing the capabilities of the native tools is, in my opinion, a net loss, and quite frustrating at times…

Well thanks for your explanation but I’m not sure how to take this news…
I was hoping folks like yourself who hold arcane knowledge of sketchup’s inner workings might be able to shed a little light on this subject…Alas.

I never need the Dave Method (i’d just change units from mm to m) but I do often run in to validity check errors… I might uncheck the Fix Problems Automatically box and see if that improves my error-rate. My errors step from imported (autocad or similar) geometry of high complexity.

I have been tempted to do this, but I leave checking enabled because I figure someday it’s going to happen inadvertently. When it did the model would be destroyed due to a large accumulation of tiny geometry. I would rather live with some extra time occasionally spent repairing what SketchUp still cannot handle at 100X scale than take that risk. I also want any other person who uses my model to not face such destruction when they open and re-save it.