01:53 <Guest12> How to use Measure Distance from Design menu?

01:54 <teepee> it needs preferences->features->manifold enabled

01:56 <Guest12> OK, but then what? How is it used?

01:57 <teepee> generate a mesh with f6

01:57 <teepee> select measure

01:57 <teepee> point to vertices or edges

01:58 <teepee> https://www.youtube.com/watch?v=LA9lsDdwhTA

01:58 <othx> teepee linked to YouTube video "OpenSCAD improvement measurement tools" => 3 IRC mentions

02:00 <gbruno> [github] ostat opened issue #5150 (textmetrics does not work from command line) https://github.com/openscad/openscad/issues/5150

02:01 <gbruno> [github] t-paul closed issue #5150 (textmetrics does not work from command line) https://github.com/openscad/openscad/issues/5150

02:09 <Guest12> One of the YouTube comments is that this works only on "new" models, not on old models loaded in.

02:12 <Guest12> In fact, I just verified it. Do this is not that useful...

02:14 <teepee> that sounds unlikely

02:15 <teepee> and it's not true

02:17 <Guest12> I just opened an old design, and Measure Distance / Angle do not work. But if I start a new design, they work.

02:20 <teepee> open, press F6!, measure

02:26 <Guest12> YES!!  It does work, but not always. That is why someone else said it does not work. I will have to play more with it to see what makes it fail on some old models. Thank you!

02:29 <teepee> yes, if you find some scenario where you can reproduce the not-working state, a bugreport on github would be good

02:29 <teepee> I only found I sometimes need to rotate things a bit to catch the edges I want to select

02:32 <Guest12> I will have to investigate more tomorrow. I will report if I can figure it out. Good night.

04:06 <peeps[zen]> sounds like maybe they were importing an stl or something, which then wouldn't be processed by geometry engine for f6?

04:08 <Guest76> https://www.thingiverse.com/thing:6603358

04:08 <othx> Guest76 linked to "Fairy stencil 5 by Longquang" on thingiverse => 1 IRC mentions

12:23 <cart_man> Hey everyone. I am trying to make a polygon with a round edge. I find it pretty hard to do using only x,y coordinates. Is there a way to smooth out an edge with some tool? Here is my weird edge that is not working out. -> https://pastebin.com/V7TDZSfc

12:24 <cart_man> So basically I would just like the edge at 65,10 to go back to the Y axis smoothly up until its at Y=15.

12:51 <InPhase> cart_man: A triangle with the top right corner rounded?

12:51 <InPhase> cart_man: And the others pointy?

12:52 <InPhase> Or will this polygon do other things and have other rounded parts?

12:58 <InPhase> The simplest polygonal rounding is from slapping offset calls outside of a polygon call. e.g. one interpretation of what you're asking: $fs=1; $fa=1; polygon(points=[[0,0],[65,0],[65,15/2],[65,15]/2]); offset(2) offset(-2) polygon([[0,0],[65,0],[65,15]]);

12:59 <J24k5> offset can round all convex or concave .. selective is only possible with a function that inserts arcs at the point. https://user-images.githubusercontent.com/93376232/175875266-c4586e59-5f45-46f4-a2f1-120fd8cab591.png

13:01 <InPhase> cart_man: Notice two polygon calls, which you could display separately to see the magic. I made a rounded version, and then a pointy version but just cut one corner off by going only halfway there, giving one rounded edge and 2 pointy edges.

13:02 <cart_man> InPhase: Whow tha is perfect!

13:02 <InPhase> Unlike polyhedron, polygon you can get away with just overlapping stuff.

13:03 <InPhase> cart_man: The trickiest reasoning was [65,15]/2, but that was literally a point average, ([65,15]+[0,0])/2, which is the midpoint.

13:04 <InPhase> cart_man: You can also generate a whole bunch of polygon points to include with a list comprehension... But that requires a bit more math thinking.

13:10 <InPhase> cart_man: An illustration: polygon([[0,0],[65,0],each [for (a=[0:floor(270+atan2(-15,-65))]) echo(a) 2*[cos(a),sin(a)]+[63,13]]]);

13:15 <InPhase> The echo is for informational purposes only, and can be removed.

13:51 <cart_man> So I am trying to figure out what is going on with the Trig. While I am doing that I copy and pasted the example into my model and it fit perfectly. As a result I hit f6 to render it but I got -> ERROR: The given mesh is not closed! Unable to convert to CGAL_Nef_Polyhedron.

13:52 <cart_man> Btw at the 0 point it can be a block. So the rounding is perfect but the top can be flat with the last point at [0,15]

13:52 <cart_man> InPhase: ^^

13:58 <cart_man> InPhase: Whow the is a lot going on in a short span of code. It is a bit hard to deciminate

14:08 <InPhase> Surely you didn't get a "not closed" from that polygon I showed. :)

14:09 <InPhase> But there are lots of ways to get not closed in a design. You might need to pastebin the thing giving that error.

14:10 <InPhase> cart_man: And when trying to understand it, it can be helpful sometimes to rip things out. Sometimes I get errors when making such things, and what I do is pull them out of the polygon calls, and work from the inside out, feeding things into echo, so I can see the numbers it's actually working with.

14:11 <InPhase> cart_man: This helps a lot for building an understanding of what a thing is doing, what it's not doing, and what it's doing wrong when a mistake is made.

14:15 <InPhase> cart_man: My "logic" for it was finding the orientation angles of the edges, which go from 90 to atan2(-15,-65), where those numbers are the xy vector from the top right triangle point back to the point at the origin. Because atan2 gives -180 to 180, I had to add 360 because it was a negative value. Then I wanted the orientation angle for the edges of the circle from the radius, which were 90 degrees

14:15 <InPhase> rotated to the right, so my loop was over angles that were 90 degrees less than that, so the 0 and 270 appeared.

14:15 <InPhase> cart_man: Then I picked a radius 2, and my origin moved 2 in from the corner point, which gives the other numbers.

14:18 <Guest70> was kannst du

14:18 <cart_man> InPhase: I am sure it is some functions I run ontop of the polygon you gave me

14:21 <InPhase> cart_man: My math version had a small approximation error with the 13, which didn't bother to take into account that it should move down enough to make the angled part 2 rather than the y direction, but it has no aesthetic impact, and you didn't specify strict sizing needs, so I left it. If you had tighter constraints, there might be some extra math on that sort of thing. :)

14:51 <cart_man> InPhase: I use to know how to use Trig in University but damn would I love to be able to do what you just did with it

14:56 <InPhase> If you know the basic steps you can work such things out slowly on paper. I just did it faster from a lot of trigonometric manipulation practice. It gets a little speedier as you keep adding zeros to the right of the number of times you repeatedly do it.

14:58 <InPhase> If you need to do it the careful deliberate way, sketch it and start labeling things carefully.

16:10 <cart_man> InPhase: I have an idea for the OpenSCad community and exposure to newbies.

16:11 <cart_man> InPhase: A course on manipulating polygons with Trig functions.

16:12 <teepee> cool, who is going to do it?

16:14 <teepee> there *is* a book about it (I think) https://openscad.org/documentation-books.html - Make: Trigonometry

16:34 <InPhase> teepee: It sounds like that's more about using OpenSCAD as an aid for learning trig.

16:34 <InPhase> Which is also useful.

16:34 <InPhase> I think it would make a wonderful supplement for a trig course though, to use OpenSCAD, if you used it in both ways.

16:35 <teepee> I did not have a closer look yet, I got all the Make books via humble-bundle not long ago

16:35 <InPhase> cart_man: So really what you need isn't basic trig, but thinking about vector manipulation. The mindsets I use when I do that mostly come from my physics background.

16:35 <InPhase> cart_man: Trig is just a tool for that, but there aren't a whole lot of trig elements involved.

16:36 <teepee> well, all those 3 openscad make books from joan and rich ;-)

16:38 <InPhase> cart_man: sin, cos, tan, atan2, the pythagorean theorem, an understanding of the transformations between Cartesian, cylindrical, and spherical coordinate systems, and then a whole lot of thinking about vector transformations. A background in actually understanding how an affine transformation is done with a matrix, or being able to do its parts separately, is helpful for the most advanced stuff.

16:38 <InPhase> That's most of it.

16:39 <InPhase> One could fit the trig elements onto an index card.

16:42 <InPhase> When working with points directly I also find myself doing various methods of interpolation and extrapolation too, but the majority of this falls right out of standard vector operations.

16:44 <InPhase> cart_man: I'll tell you what. You find me 50,000 people who want to commit to buying the book, and I'll write it. ;)

16:45 <teepee> oh, ffs, gitlab... "The most-comprehensive AI-powered DevSecOps platform"

16:45 <teepee> there has to be some really potent stuff they all are sniffing :(

16:46 <InPhase> kintel: By the way, do you know approximately how many copies of your OpenSCAD book sold since it was released?

16:46 <cart_man> InPhase: Hah well could be amazing if a UNi or a schoool adopts OpenSCad as a learning util

16:47 <InPhase> cart_man: I used OpenSCAD in a course I used to run, as a hands-on asset for teaching physics to non-science majors.

16:47 <teepee> some have (or some teachers have) from what I've seen on twitter over the years, but it's not very public

16:47 <InPhase> cart_man: Back when I was a prof.

16:47 <teepee> I'd love to have a "for teachers" section on the website, but we need some connections to people to get this started

16:48 <InPhase> cart_man: I hit it up as dual use, using it to trick them into actually thinking about coordinates and such in a visual manner, while also having them design and refine printable model rockets.

16:48 <cart_man> There are tons of books on that page actually WHOW!

16:48 <teepee> same with accessibility, there's a couple of courses for vision impaired people doing 3d printing using openscad

16:48 <cart_man> InPhase: That is awesome though!

16:49 <InPhase> I don't have any of those assets in distributable-to-everyone format, but I'd share them with any instructor wanting to attempt the same.

16:50 <InPhase> It really wasn't a very hard section to run, as long as one knows OpenSCAD well enough to help the students when they get stuck early on.

16:51 <InPhase> Reviews consistently put that as their favorite part of the course.

19:28 <cart_man> InPhase: That is great! I hope they remember how easy it was to do things with OpenSCad. I previously used Blender and then TinkerCad and changing things down the line was such a missions and also Blender was quite bad with rendering some differences or merged objects at times