Parts cut away with difference() still remains in some situations
Try this minimalistic code sample:
union(){
color([0.5,0.5,0.5])
cube([50,100,100]);
difference(){
cube([100,100,100]);
translate([-1,-1,-1])
cube([51,102,102]);
}
}
It looks like a mess, with typical "in the same plane hatching".
I've seen this in other situations as well, so I don't think it's a bug in
my code. You can try to comment out the first cube, just to see that the cut
done by difference() is correct.
Shouldn't the cut away parts be gone?
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You need to avoid coincident faces (even removed ones) if you want the
OpenCSG preview to look OK, or use render() to calculate the geometry
before preview.
union(){
color([0.5,0.5,0.5])
cube([50,100,100]);
render() difference(){
cube([100,100,100]);
translate([-1,-1,-1])
cube([52,102,102]);
}
}
On 9 November 2017 at 08:51, Troberg troberg.anders@gmail.com wrote:
Try this minimalistic code sample:
union(){
color([0.5,0.5,0.5])
cube([50,100,100]);
difference(){
cube([100,100,100]);
translate([-1,-1,-1])
cube([51,102,102]);
}
}
It looks like a mess, with typical "in the same plane hatching".
I've seen this in other situations as well, so I don't think it's a bug in
my code. You can try to comment out the first cube, just to see that the
cut
done by difference() is correct.
Shouldn't the cut away parts be gone?
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Thanks! Fixed it by moving the surfaces a tiny fraction of a millimeter.
Here's the code I was trying to make, a protractor for on-screen measuring
within a model, a companion to the ruler I've posted earlier. Maybe someone
finds it useful.
module protractor(radius, innerradius){
w=radius-innerradius;
protractorscale(90, innerradius+w/2, innerradius);
protractorscale(45, innerradius+w/2+w/4, innerradius+w/2);
protractorscale(10, innerradius+w/2+w/4+w/8, innerradius+w/2+w/4);
protractorscale(5, innerradius+w/2+w/4+w/8+w/16,
innerradius+w/2+w/4+w/8);
protractorscale(1, radius, innerradius+w/2+w/4+w/8+w/16);
color([0,0,0])
translate([-innerradius,-1/2,0])
cube([innerradius*2,1,1]);
color([0,0,0])
translate([-1/2,-innerradius,0])
cube([1,innerradius*2,1]);
}
module protractorscale(step, radius, innerradius){
difference(){
for(n=[0:step:360]){
union(){
color([(n/step)%2,(n/step)%2,(n/step)%2])
translate([0,0,step/400])
linear_extrude(height=1+step/200)
polygon([[0,0],[sin(n)radius2,cos(n)radius2],[sin(n+step)radius2,cos(n+step)radius2]]);
}
}
difference(){
color([0,0,0])
translate([0,0,-1])
cylinder(r=radius*3,3,$fn=360);
difference(){
color([0,0,0])
translate([0,0,-2])
cylinder(r=radius,5,$fn=360);
color([0,0,0])
translate([0,0,-3])
cylinder(r=innerradius,7,$fn=360);
}
}
}
}
//Test
protractor(200,150);
--
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Nice but very slow to pan and zoom on my system due to the number of
objects.
To make it smooth I would put all the put some renders() in at the top
level and then apply colour. That will be slow once to calculate but it is
then cached and drawn quickly. That is how I make big assemblies like 3D
printers with hundreds of parts.
On 9 November 2017 at 10:03, Troberg troberg.anders@gmail.com wrote:
Thanks! Fixed it by moving the surfaces a tiny fraction of a millimeter.
Here's the code I was trying to make, a protractor for on-screen measuring
within a model, a companion to the ruler I've posted earlier. Maybe someone
finds it useful.
module protractor(radius, innerradius){
w=radius-innerradius;
protractorscale(90, innerradius+w/2, innerradius);
protractorscale(45, innerradius+w/2+w/4, innerradius+w/2);
protractorscale(10, innerradius+w/2+w/4+w/8, innerradius+w/2+w/4);
protractorscale(5, innerradius+w/2+w/4+w/8+w/16,
innerradius+w/2+w/4+w/8);
protractorscale(1, radius, innerradius+w/2+w/4+w/8+w/16);
color([0,0,0])
translate([-innerradius,-1/2,0])
cube([innerradius*2,1,1]);
color([0,0,0])
translate([-1/2,-innerradius,0])
cube([1,innerradius*2,1]);
}
module protractorscale(step, radius, innerradius){
difference(){
for(n=[0:step:360]){
union(){
color([(n/step)%2,(n/step)%2,(n/step)%2])
translate([0,0,step/400])
linear_extrude(height=1+step/200)
polygon([[0,0],[sin(n)radius2,cos(n)radius2],[sin(n+
step)radius2,cos(n+step)radius2]]);
}
}
difference(){
color([0,0,0])
translate([0,0,-1])
cylinder(r=radius*3,3,$fn=360);
difference(){
color([0,0,0])
translate([0,0,-2])
cylinder(r=radius,5,$fn=360);
color([0,0,0])
translate([0,0,-3])
cylinder(r=innerradius,7,$fn=360);
}
}
}
}
//Test
protractor(200,150);
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As another nice touch, avoid the proctator to be rendered by an
accidentally hit F6. Just insert a % between the color and render()
suggested by nophead. That is what I do in my ruler code.
Em 9 de nov de 2017 08:22, "nop head" nop.head@gmail.com escreveu:
Nice but very slow to pan and zoom on my system due to the number of
objects.
To make it smooth I would put all the put some renders() in at the top
level and then apply colour. That will be slow once to calculate but it is
then cached and drawn quickly. That is how I make big assemblies like 3D
printers with hundreds of parts.
On 9 November 2017 at 10:03, Troberg troberg.anders@gmail.com wrote:
Thanks! Fixed it by moving the surfaces a tiny fraction of a millimeter.
Here's the code I was trying to make, a protractor for on-screen measuring
within a model, a companion to the ruler I've posted earlier. Maybe
someone
finds it useful.
module protractor(radius, innerradius){
w=radius-innerradius;
protractorscale(90, innerradius+w/2, innerradius);
protractorscale(45, innerradius+w/2+w/4, innerradius+w/2);
protractorscale(10, innerradius+w/2+w/4+w/8, innerradius+w/2+w/4);
protractorscale(5, innerradius+w/2+w/4+w/8+w/16,
innerradius+w/2+w/4+w/8);
protractorscale(1, radius, innerradius+w/2+w/4+w/8+w/16);
color([0,0,0])
translate([-innerradius,-1/2,0])
cube([innerradius*2,1,1]);
color([0,0,0])
translate([-1/2,-innerradius,0])
cube([1,innerradius*2,1]);
}
module protractorscale(step, radius, innerradius){
difference(){
for(n=[0:step:360]){
union(){
color([(n/step)%2,(n/step)%2,(n/step)%2])
translate([0,0,step/400])
linear_extrude(height=1+step/200)
polygon([[0,0],[sin(n)radius2,cos(n)radius2],[sin(n+step
)radius2,cos(n+step)radius2]]);
}
}
difference(){
color([0,0,0])
translate([0,0,-1])
cylinder(r=radius*3,3,$fn=360);
difference(){
color([0,0,0])
translate([0,0,-2])
cylinder(r=radius,5,$fn=360);
color([0,0,0])
translate([0,0,-3])
cylinder(r=innerradius,7,$fn=360);
}
}
}
}
//Test
protractor(200,150);
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That would mean that I would first have to make all the white objects, then
all the black. Too much work for an occasional measurement...
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