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3D Primitives

Introduction

Resolution of Shapes

All rounded shapes have a resolution option which controls tesselation. If resolution is set to 8, then 8 polygons are used to create 360 degrees of revolution.

This allows each design to control the amount of detail present, but beware that calculations and rendering time will also increase. For example, the number of polygons increases quadratically with each increase of the resolution for spheres.

EXAMPLE

If the resolution option is omitted, the following resolution is used.

  • CSG.defaultResolution3D

OpenSCAD like functions support the fn parameter, which is the same as resolution.

Cuboid

A three dimensional shape created from six retangular faces, each at right angles to another, and opposite faces are equal. The cube is a special case of the a cuboid in which all six faces are squares.

 Cuboid

Learn about cuboids at MathIsFun.com

Cubes can be created at a requested center. The radius specifies the size of the faces. Cubes with different radius for X, Y and Z axis can be specified by supplying an array of values.

Defaults:

  • size : 1 or [1,1,1]
  • center : [0,0,0]
  • radius : 0
  • round: false
cube({size: 1})
cube({size: [1,2,3]})
cube({size: 1, center: true}) // default center:false
cube({size: 1, center: [false,false,false]}) // individual axis center true or false
cube({size: [1,2,3], round: true})

Also, the CSG library functions can be used directly. NOTE Deprecated in the V2 API

CSG.cube({
    center: [0, 0, 0],
    radius: [1, 1, 1]
})
 
CSG.cube({ // define two opposite corners
    corner1: [4, 4, 4],
    corner2: [5, 4, 2]
})

Rounded cubes are created by specifying a rounded radius for the corners and the sides.

CSG.roundedCube({ // rounded cube
    center: [0, 0, 0],
    radius: 1,
    roundradius: 0.9,
    resolution: 8,
});

Sphere

Spheres can be created like this:

sphere(1);
sphere({r: 2});                    // Note: center:true is default (unlike other primitives, as OpenSCAD)
sphere({r: 2, center: true});     // Note: OpenSCAD doesn't support center for sphere but we do
sphere({r: 2, center: [false, false, true]}); // individual axis center 
sphere({r: 10, fn: 100 });
sphere({r: 10, fn: 100, type: 'geodesic'});  // geodesic approach (icosahedron further triangulated)
 
CSG.sphere({
  center: [0, 0, 0],
  radius: 2,                      // must be scalar
  resolution: 128
});

In case of ``type: 'geodesic'`` the fn tries to match the non-geodesic fn, yet, actually changes in steps of 6 (e.g. fn=6..11 is the same), fn = 1 reveals the base form: the icosahedron.

Cylinder

Cylinders and cones can be created like this:

cylinder({r: 1, h: 10});                 // openscad like
cylinder({d: 1, h: 10});
cylinder({r: 1, h: 10, center: true});   // default: center:false
cylinder({r: 1, h: 10, center: [true, true, false]});  // individual x,y,z center flags
cylinder({r: 1, h: 10, round: true});
cylinder({r1: 3, r2: 0, h: 10});
cylinder({d1: 1, d2: 0.5, h: 10});
cylinder({start: [0,0,0], end: [0,0,10], r1: 1, r2: 2, fn: 50});
 
CSG.cylinder({                      //using the CSG primitives
  start: [0, -1, 0],
  end: [0, 1, 0],
  radius: 1,                        // true cylinder
  resolution: 16
});
CSG.cylinder({
  start: [0, -1, 0],
  end: [0, 1, 0],
  radiusStart: 1,                   // start- and end radius defined, partial cones
  radiusEnd: 2,
  resolution: 16
});
CSG.roundedCylinder({               // and its rounded version
  start: [0, -1, 0],
  end: [0, 1, 0],
  radius: 1,
  resolution: 16
});

Torus

A three dimensional shape made by revolving a small circle (inner) along the circumference a bigger circle (outer).

 Torus

Learn about torus at MathIsFun.com

A torus is defined as such:

  • Inner Circle
    • ri = inner radius
    • fni = inner resolution
    • roti = inner rotation
  • Outer Circle
    • ro = outer radius
    • fno = outer resolution

Note: See the start of 3D Primitives for information about the resolution of three dimensional shapes.

Defaults:

  • ri : 1
  • fni : 16
  • roti : 0
  • ro : 4
  • fno : 32
torus() 
torus({ ri: 1.5, ro: 3 })
torus({ ri: 0.2 })
 
torus({ fni:4 })           // make inner circle fn = 4 => square
torus({ fni:4,roti:45 })   // rotate inner circle, so flat is top/bottom
torus({ fni:4,fno:4,roti:45 })
torus({ fni:4,fno:5,roti:45 })