eps = 0.01;

// create and cut the base properly

difference() {

    // base piece to be cut into

    color("yellow")

    translate ([eps,0,-6]) cube([20,20,6]);

    // vertical piece with tab

    color("green")

    union(){

        cube([6,20,30]);

        translate ([0,5,-6-eps])   cube([6,10,6+eps]);

    }

}

/* this part was discarded after the difference operation,

 so need to recreate it */

// vertical piece with tab

color("red")

union(){

    cube([6,20,30]);

    translate ([0,5,-6-eps])   cube([6,10,6+eps]);

}

Hello everyone, I am hoping to be able to design parametric drawer inserts for lasercutting. Here is a simple example of a two-part lasercuttable 3D form: ``` eps = 0.01; ``` ``` // create and cut the base properly ``` ``` difference() { ``` ``` ``` ``` // base piece to be cut into ``` ``` color("yellow") ``` ``` translate ([eps,0,-6]) cube([20,20,6]); ``` ``` ``` ``` // vertical piece with tab ``` ``` color("green") ``` ``` union(){ ``` ``` cube([6,20,30]); ``` ``` translate ([0,5,-6-eps]) cube([6,10,6+eps]); ``` ``` } ``` ``` } ``` ``` /* this part was discarded after the difference operation, ``` ``` so need to recreate it */ ``` ``` // vertical piece with tab ``` ``` color("red") ``` ``` union(){ ``` ``` cube([6,20,30]); ``` ``` translate ([0,5,-6-eps]) cube([6,10,6+eps]); ``` ``` } ``` I have a two questions: 1) Can I export two distinct DXFs from this file, one of an XY face of the yellow body, and one of a XZ face of the red body? (I’d need to do this to be able to lasercut.) 2) Is there a way to tell OpenSCAD not to discard the subtrahend of the difference operation? In CAD software, this would be an option called something like “keep cutting tool.” I’m aware of the # symbol in front of a command for displaying the ghost of the body; that’s not what I’m looking for. Thanks!

     // base piece to be cut into

 color("yellow")

 translate ([eps,0,-6]) cube([20,20,6]);

     // vertical piece with tab

 color("green")

 union(){

     cube([6,20,30]);

     translate ([0,5,-6-eps])   cube([6,10,6+eps]);

 }

 cube([6,20,30]);

 translate ([0,5,-6-eps])   cube([6,10,6+eps]);

1) you can use projection() https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Using_the_2D_Subsystem#3D_to_2D_Projection 2) No. But you can make an module(){} out of the difference object and just use it twice (as difference and as extra object) Am Do., 19. Aug. 2021 um 18:02 Uhr schrieb <bobby.zacharias@gmail.com>: > Hello everyone, > > I am hoping to be able to design parametric drawer inserts for > lasercutting. > > Here is a simple example of a two-part lasercuttable 3D form: > > eps = 0.01; > > // create and cut the base properly > > difference() { > > // base piece to be cut into > > color("yellow") > > translate ([eps,0,-6]) cube([20,20,6]); > > // vertical piece with tab > > color("green") > > union(){ > > cube([6,20,30]); > > translate ([0,5,-6-eps]) cube([6,10,6+eps]); > > } > > } > > /* this part was discarded after the difference operation, > > so need to recreate it */ > > // vertical piece with tab > > color("red") > > union(){ > > cube([6,20,30]); > > translate ([0,5,-6-eps]) cube([6,10,6+eps]); > > } > > I have a two questions: > > 1) Can I export two distinct DXFs from this file, one of an XY face of the > yellow body, and one of a XZ face of the red body? (I’d need to do this to > be able to lasercut.) > > 2) Is there a way to tell OpenSCAD not to discard the subtrahend of the > difference operation? In CAD software, this would be an option called > something like “keep cutting tool.” I’m aware of the # symbol in front of a > command for displaying the ghost of the body; that’s not what I’m looking > for. > > Thanks! > _______________________________________________ > OpenSCAD mailing list > To unsubscribe send an email to discuss-leave@lists.openscad.org >

module colordiff(colors) {
    assert(len(colors) == $children);
    color(colors[0]) difference() {
        children(0);
        for (i=[1:$children-1]) children(i);
    }
    for (i = [1:$children-1]) color(colors[i]) children(i);
}

colordiff(["red", "white", "blue"]) {
    cube(10);
    translate([5,5,5]) cube(10);
    translate([-5,-5,-5]) cube(10);
}

On 8/19/2021 9:02 AM, bobby.zacharias@gmail.com wrote: > > 1) Can I export two distinct DXFs from this file, one of an XY face of > the yellow body, and one of a XZ face of the red body? (I’d need to do > this to be able to lasercut.) > One run can yield only one output.  However, you could have a flag that you could set to say which of the two outputs you want to produce.  You could set the flag manually by editing the program, or you could rig it for the customizer, or you could rig it so that you do the final renders from the CLI with a script. I have some tooling - a couple of OpenSCAD modules and a shell script - that let me have a single OpenSCAD file that generates several parts, to be rendered one at a time or in combinations.  In my particular case, I want to generate PNGs of parts or combinations of parts, and STLs of individual parts (for printing) or combinations of parts (for visualization).  I run the script and it runs the OpenSCAD program once to collect an inventory of what is to be done, then runs OpenSCAD once for each file to be created.  I'm happy to share that if you're interested. > 2) Is there a way to tell OpenSCAD not to discard the subtrahend of > the difference operation? In CAD software, this would be an option > called something like “keep cutting tool.” I’m aware of the # symbol > in front of a command for displaying the ghost of the body; that’s not > what I’m looking for. > What does this really mean?  If you "keep" the subtrahend, what would happen to it?  If you keep it straightforwardly, it'd just be unioned back into the difference, for a net result of zero change. In your example, the first thing I would think of would be to wrap that subtrahend in a module, so you don't have to duplicate it. It looks like you want the subtrahend to be a different color.  Here's a module that would do something like that. module colordiff(colors) { assert(len(colors) == $children); color(colors[0]) difference() { children(0); for (i=[1:$children-1]) children(i); } for (i = [1:$children-1]) color(colors[i]) children(i); } colordiff(["red", "white", "blue"]) { cube(10); translate([5,5,5]) cube(10); translate([-5,-5,-5]) cube(10); } But:  because of OpenSCAD's somewhat limited color mechanisms, I'm not sure that's different from just creating the three cubes as overlapping objects.  Also I suspect that there will be Z-fighting if they share faces.