minkowski3d_3.as - Demonstrates 3d filetting using minkowski

minkowski3d_3_1.md

// AngelCAD sample: minkowski3d_3.as
// Demonstrates 3d filetting using minkowski3d

solid@ object(double sz)
{
   // cuboids extending in 3 axis directions
   return   translate(-sz,0,0) * cuboid(2*sz,sz,sz)
          + translate(0,-sz,0) * cuboid(sz,2*sz,sz)
          + cuboid(sz,sz,2*sz);
}

solid@ erode(solid@ obj, double r)
{
   // create a cube enclosing the object completely
   // with an internal void shaped by the object
   double diag = obj.box().diagonal();
   solid@ d1 = cube(diag*2,center:true) - obj;
   
   // make the void smooth
   solid@ m1 = minkowski3d(d1,sphere(r));
   return obj - m1;
}

shape@ main_shape()
{
   return erode(object(sz:100),20.0);
}

void main()
{
   shape@ obj = main_shape();
   
   // export as .xcsg 
   obj.write_xcsg(GetInputFullPath(),secant_tolerance:0.01);
   
   // export as OpenScad .csg
   obj.write_csg(GetInputFullPath());
}

minkowski3d_3_2_angelcad.png

minkowski3d_3_3.csg

// This file was created using AngelCAD (as_csg) v1.3-02
// Copyright(C) 2015-2018 Carsten Arnholm, http://arnholm.org/ 
// Open it with OpenSCAD for display or further processing 
$fn = 60;
$fa = 6.0;
$fs = 1.0;
group() {
	multmatrix([[1,0,0,0],[0,1,0,0],[0,0,1,0],[0,0,0,1]]) {
		difference() {
			multmatrix([[1,0,0,0],[0,1,0,0],[0,0,1,0],[0,0,0,1]]) {
				union() {
					multmatrix([[1,0,0,0],[0,1,0,0],[0,0,1,0],[0,0,0,1]]) {
						union() {
							multmatrix([[1,0,0,-100],[0,1,0,0],[0,0,1,0],[0,0,0,1]]) {
								cube( size=[200, 100, 100] , center=false );
							}
							multmatrix([[1,0,0,0],[0,1,0,-100],[0,0,1,0],[0,0,0,1]]) {
								cube( size=[100, 200, 100] , center=false );
							}
						}
					}
					multmatrix([[1,0,0,0],[0,1,0,0],[0,0,1,0],[0,0,0,1]]) {
						cube( size=[100, 100, 200] , center=false );
					}
				}
			}
			multmatrix([[1,0,0,0],[0,1,0,0],[0,0,1,0],[0,0,0,1]]) {
				minkowski() {
					multmatrix([[1,0,0,0],[0,1,0,0],[0,0,1,0],[0,0,0,1]]) {
						difference() {
							multmatrix([[1,0,0,0],[0,1,0,0],[0,0,1,0],[0,0,0,1]]) {
								cube( size=[692.820323028, 692.820323028, 692.820323028], center=true );
							}
							multmatrix([[1,0,0,0],[0,1,0,0],[0,0,1,0],[0,0,0,1]]) {
								union() {
									multmatrix([[1,0,0,0],[0,1,0,0],[0,0,1,0],[0,0,0,1]]) {
										union() {
											multmatrix([[1,0,0,-100],[0,1,0,0],[0,0,1,0],[0,0,0,1]]) {
												cube( size=[200, 100, 100] , center=false );
											}
											multmatrix([[1,0,0,0],[0,1,0,-100],[0,0,1,0],[0,0,0,1]]) {
												cube( size=[100, 200, 100] , center=false );
											}
										}
									}
									multmatrix([[1,0,0,0],[0,1,0,0],[0,0,1,0],[0,0,0,1]]) {
										cube( size=[100, 100, 200] , center=false );
									}
								}
							}
						}
					}
					multmatrix([[1,0,0,0],[0,1,0,0],[0,0,1,0],[0,0,0,1]]) {
						sphere( r=20 );
					}
				}
			}
		}
	}
}

minkowski3d_3_4_openscad.png