missing parts on review (f5), but correct on render (f6)
Hi there,
I have constructed a polygon, which I extrude and then a build an object
from it by rotation. I then difference a cylinder to construct a pneumatic
cylinder body.
Upon f5, it leaves out weird surfaces all over the place, but on f6 it is a
solid.
I tried convexity, but it seems to do nothing, or maybe I used it in the
wrong place(s).
Anybody, can this be resolved since it is a pain in the neck when you are
constructing visually to see if things will fit, but you have to render
every time? Can take very long with large part counts.
my code:
$fn=64;
polygon_points
=[[-38,-35],[-35,-38],[-21,-38],[-20,-37],[-9,-37],[-9,-35],[-10,-35],[-10,-34],[-1,-34],[-1,-37],[1,-37],[1,-34],[10,-34],[10,-35],[9,-35],[9,-37],[20,-37],[21,-38],[35,-38],[38,-35],[38,-22.5],[-38,-22.5],[-38,-35]];
module
upright_side(){linear_extrude(56)polygon(polygon_points,convexity=20);
}
difference(){union(){
upright_side();
rotate([0,0,180])upright_side();
rotate([0,0,90])upright_side();
rotate([0,0,270])upright_side();
}
translate([0,0,-0.5])cylinder(h=57,d=65);
}
I would like some of the longer standing members to have a look, and
explain to me how to improve on this. I also noticed this with certain
imported stl files. Convexity can sort most of them but sometimes after a
difference the whole import stl disappears, also annoying and I have some
feeling it has to do with the same issue.
Kind regards and thanks,
Kees "3dcase" Bijker
Add the convexity parameter to linear_extrude().
On Wed, 30 Nov 2022 at 12:44, kornelis bijker kornelis030465@gmail.com
wrote:
Hi there,
I have constructed a polygon, which I extrude and then a build an object
from it by rotation. I then difference a cylinder to construct a pneumatic
cylinder body.
Upon f5, it leaves out weird surfaces all over the place, but on f6 it is
a solid.
I tried convexity, but it seems to do nothing, or maybe I used it in the
wrong place(s).
Anybody, can this be resolved since it is a pain in the neck when you are
constructing visually to see if things will fit, but you have to render
every time? Can take very long with large part counts.
my code:
$fn=64;
polygon_points
=[[-38,-35],[-35,-38],[-21,-38],[-20,-37],[-9,-37],[-9,-35],[-10,-35],[-10,-34],[-1,-34],[-1,-37],[1,-37],[1,-34],[10,-34],[10,-35],[9,-35],[9,-37],[20,-37],[21,-38],[35,-38],[38,-35],[38,-22.5],[-38,-22.5],[-38,-35]];
module
upright_side(){linear_extrude(56)polygon(polygon_points,convexity=20);
}
difference(){union(){
upright_side();
rotate([0,0,180])upright_side();
rotate([0,0,90])upright_side();
rotate([0,0,270])upright_side();
}
translate([0,0,-0.5])cylinder(h=57,d=65);
}
I would like some of the longer standing members to have a look, and
explain to me how to improve on this. I also noticed this with certain
imported stl files. Convexity can sort most of them but sometimes after a
difference the whole import stl disappears, also annoying and I have some
feeling it has to do with the same issue.
Kind regards and thanks,
Kees "3dcase" Bijker
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
Mr. nop head's answer is the most appropriate in your case.
Also the way you are calculating the points seems to be quite complicated.
In such cases I found moving in a relative reference would be much easier
than the absolute reference e.g. to create a square of 5x5
absolute reference : [[0,0],[5,0],[5,5],[0,5]]
but if you write a function to calculate cumulative sum of points
you can write in relative reference:
some_function([[0,0],[5,0],[0,5],[-5,0]])
On Wed, 30 Nov 2022 at 18:14, kornelis bijker kornelis030465@gmail.com
wrote:
Hi there,
I have constructed a polygon, which I extrude and then a build an object
from it by rotation. I then difference a cylinder to construct a pneumatic
cylinder body.
Upon f5, it leaves out weird surfaces all over the place, but on f6 it is
a solid.
I tried convexity, but it seems to do nothing, or maybe I used it in the
wrong place(s).
Anybody, can this be resolved since it is a pain in the neck when you are
constructing visually to see if things will fit, but you have to render
every time? Can take very long with large part counts.
my code:
$fn=64;
polygon_points
=[[-38,-35],[-35,-38],[-21,-38],[-20,-37],[-9,-37],[-9,-35],[-10,-35],[-10,-34],[-1,-34],[-1,-37],[1,-37],[1,-34],[10,-34],[10,-35],[9,-35],[9,-37],[20,-37],[21,-38],[35,-38],[38,-35],[38,-22.5],[-38,-22.5],[-38,-35]];
module
upright_side(){linear_extrude(56)polygon(polygon_points,convexity=20);
}
difference(){union(){
upright_side();
rotate([0,0,180])upright_side();
rotate([0,0,90])upright_side();
rotate([0,0,270])upright_side();
}
translate([0,0,-0.5])cylinder(h=57,d=65);
}
I would like some of the longer standing members to have a look, and
explain to me how to improve on this. I also noticed this with certain
imported stl files. Convexity can sort most of them but sometimes after a
difference the whole import stl disappears, also annoying and I have some
feeling it has to do with the same issue.
Kind regards and thanks,
Kees "3dcase" Bijker
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org