round-anything/MinkowskiRound.scad

// Library: MinkowskiRound.scad
// Version: 1.0
// Author: IrevDev
// Copyright: 2020
// License: MIT

/*
---Modules
round2d(outside radius,internal radius) -> takes 2d children
This module will round 2d any shape

minkowskiRound(outsideRadius,internalRadius,enable,envelopecube[x,y,z]) -> takes 3d children
This module will round any 3d shape though it takes a long time, possibly more than 12 hours (use a low $fn value, 10-15 to begin with) so make sure enable is set to 0 untill you are ready for final render,the envelopecube must be bigger than the object you are rounding, default values are [500,500,500].

minkowskiOutsideRound(radius,enable,envelopecube[x,y,z])
minkowskiInsideRound(radius,enable,envelopecube[x,y,z])
Both this modules do the same thing as minkowskiRound() but focus on either inside or outside radiuses, which means these modules use one less minkowski() (two instead of three) making them quicker if you don't want both inside and outside radiuses.

--Examples
*/

//round2d(1,6)difference(){square([20,20]);square([10,10]);}
//minkowskiRound(3,1.5,1)theshape();
//minkowskiInsideRound(3,1)theshape();
//minkowskiOutsideRound(3,1)theshape();

//---good test child for examples
//module theshape(){//example shape
//    difference(){
//        cube([20,20,20]);
//        cube([10,10,10]);
//    }
//}

// $fn=20;
// minkowskiRound(0.7,1.5,1,[50,50,50])union(){//--example in the thiniverse thumbnail/main image
//   cube([6,6,22]);
//   rotate([30,45,10])cylinder(h=22,d=10);
// }//--I rendered this out with a $fn=25 and it took more than 12 hours on my computer


module round2d(OR=3,IR=1){
  offset(OR){
    offset(-IR-OR){
      offset(IR){
        children();
      }
    }
  }
}

module minkowskiRound(OR=1,IR=1,enable=1,boundingEnvelope=[500,500,500]){
  if(enable==0){//do nothing if not enabled
    children();
  } else {
    minkowski(){//expand the now positive shape back out
      difference(){//make the negative shape positive again
        cube(boundingEnvelope-[0.1,0.1,0.1],center=true);
        minkowski(){//expand the negative shape inwards
          difference(){//create a negative of the children
            cube(boundingEnvelope,center=true);
            minkowski(){//expand the children
              children();
              sphere(IR);
            }
          }
          sphere(OR+IR);
        }
      }
      sphere(OR);
    }
  }
}

module minkowskiOutsideRound(r=1,enable=1,boundingEnvelope=[500,500,500]){
  if(enable==0){//do nothing if not enabled
    children();
  } else {
    minkowski(){//expand the now positive shape
      difference(){//make the negative positive
        cube(boundingEnvelope-[0.1,0.1,0.1],center=true);
        minkowski(){//expand the negative inwards
          difference(){//create a negative of the children
            cube(boundingEnvelope,center=true);
            children();
          }
          sphere(r);
        }
      }
      sphere(r);
    }
  }
}

module minkowskiInsideRound(r=1,enable=1,boundingEnvelope=[500,500,500]){
  if(enable==0){//do nothing if not enabled
    children();
  } else {
    difference(){//make the negative positive again
      cube(boundingEnvelope-[0.1,0.1,0.1],center=true);
      minkowski(){//expand the negative shape inwards
        difference(){//make the expanded children a negative shape
          cube(boundingEnvelope,center=true);
          minkowski(){//expand the children
            children();
            sphere(r);
          }
        }
        sphere(r);
      }
    }
  }
}