Recommendations for Best free vector and 3D design software?

Have questions or comments about Simplify3D, Slic3r, Cura, Reptier, etc? Or wondering about which CAD software to use...discuss it here...
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insta
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Re: Recommendations for Best free vector and 3D design softw

Post by insta » Wed Feb 03, 2016 4:11 am

OpenSCAD is getting in the way enough it might be easier to generate an STL from raw points programatically at this point. :?
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Tim
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Re: Recommendations for Best free vector and 3D design softw

Post by Tim » Wed Feb 03, 2016 4:22 am

insta wrote:OpenSCAD is getting in the way enough it might be easier to generate an STL from raw points programatically at this point. :?
The tesselation makes that a non-trivial problem, though.

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Tim
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Re: Recommendations for Best free vector and 3D design softw

Post by Tim » Wed Feb 03, 2016 4:33 am

Working off of Jin's excellent suggestion, the following works pretty well and is not nearly so computationally expensive. You might not have to wait days for the result. The trick here is to use a 4-sided tapered cylinder for the Minkowski hull, and rotate it 45 degrees so that the corners are square.

Code: Select all

module t() {
  scale([5, 5, 1]) text("Test");
}

minkowski() {
  linear_extrude(1) t();
  scale([2, 2, 10]) rotate([0, 0, 45]) cylinder(r1=1, r2=0, $fn=4);
}
Also, with a nod to insta's comment, if you did this, it would be wise to save the result as STL and import it back into OpenSCAD when using the text as a cut-out of another object, because the OpenSCAD will handle the STL much quicker than doing the Minkowski hull computations.
test.png
Successful test!
Last edited by Tim on Wed Feb 03, 2016 4:36 am, edited 1 time in total.

jsc
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Re: Recommendations for Best free vector and 3D design softw

Post by jsc » Wed Feb 03, 2016 4:34 am

Can't really do it in Fusion, either, turns out. You can do the draft method, but it involves manually clicking a ton of faces, which is terrible. And you can't treat text as a profile, so there goes the loft idea. You might be able to import the text as a DWG and work with it that way.

jsc
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Re: Recommendations for Best free vector and 3D design softw

Post by jsc » Wed Feb 03, 2016 4:48 am

Problem with Minkowski with a square is that you may see some artifacts at acute corners. But I think since only the top is going to be used as the impression surface, it would be okay.
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Screen Shot 2016-02-02 at 10.41.23 PM.png

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Tim
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Re: Recommendations for Best free vector and 3D design softw

Post by Tim » Wed Feb 03, 2016 4:53 am

And just to point out, that although the examples Jin and I were showing were opposite of what was asked for, to get the right effect for lettering to be cut into a surface, you just need to turn the cone upside-down.

(edit) I re-read Jules' post and realize that the idea was to make something to imprint into a surface, so the original direction was right, but what the heck, just to show what can be done. . .

(re-edit) Okay, yes, I was right the first time.

Code: Select all

module t() {
  scale([5, 5, 1]) text("Test", font="Times New Roman:style=Bold Italic");
}

minkowski() {
   linear_extrude(1) t();
   scale([2, 2, 10]) rotate([0, 0, 45]) cylinder(r1=0, r2=1, $fn=4);
}
test2.png
another test!
Last edited by Tim on Wed Feb 03, 2016 2:30 pm, edited 1 time in total.

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Jules
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Re: Recommendations for Best free vector and 3D design softw

Post by Jules » Wed Feb 03, 2016 4:58 am

Good grief I'm lost! :shock: Guess I'd better bite the bullet and learn to use Openscad one of these days....
And what the heck is a Minkowski? :lol:

I bow to the masters! That's some mad skillz, to come up with a script that fast! :D
Last edited by Jules on Wed Feb 03, 2016 2:46 pm, edited 1 time in total.

jsc
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Re: Recommendations for Best free vector and 3D design softw

Post by jsc » Wed Feb 03, 2016 5:09 am

No, Tim, I think the upside-down version is what is called for. You want the skinny side facing down, otherwise the result would be reversed, or you would be printing with the fat end. I don't really understand why you would need draft angle on what is essentially a letterpress block, but ours is not to reason why.

A Minkowski sum takes two things, and puts the second thing everywhere around the first thing. So if you take a pyramid (or upside-down pyramid) and pick a point on it, then scribble that point everywhere around the outside (and inside) of another object and take the set of all points the pyramid passed through, then the result is what you see. It is an insane operation that you will never see in a normal CAD program.

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Jules
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Re: Recommendations for Best free vector and 3D design softw

Post by Jules » Wed Feb 03, 2016 5:24 am

jsc wrote: A Minkowski sum takes two things, and puts the second thing everywhere around the first thing. So if you take a pyramid (or upside-down pyramid) and pick a point on it, then scribble that point everywhere around the outside (and inside) of another object and take the set of all points the pyramid passed through, then the result is what you see. It is an insane operation that you will never see in a normal CAD program.
:shock: Uhmmmmmm......oooooookay.

(Sorry jin, that did not help. :lol: :lol: :lol: )

And the guy wants an angle on them, he's afraid they'll get stuck in there. (I guess whatever he's using has to harden around the letter and he thinks they'll be easier to remove with a bit of a draft on them.)

I'm just floored that you guys managed to do that. Took me a couple of hours of fighting with the damned things, and it took you all about 15 minutes!

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Tim
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Re: Recommendations for Best free vector and 3D design softw

Post by Tim » Wed Feb 03, 2016 2:28 pm

jsc wrote:It is an insane operation that you will never see in a normal CAD program.
Agreed. . . but it's the only solid-geometry operation that will generate a beveled edge without referring to a specific edge, and OpenSCAD is "philosophically pure" with respect to solid geometry and doesn't know anything about edges and vertices (at least not that it's willing to tell the end user about).

Just goes to show how uncompromising philosophical purity will kill you in the end.

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