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## 2D 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.defaultResolution2D = 32

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

### Rectangle

A two dimensional shape made with four straight sides where all interior angles are right angles (90°).

The following show examples of creating rectangles. The radius specifies the size. Rectangles with different radius for X and Y axis can be specified by supplying an array of values.

Defaults:

• radius : 1 or [1,1]
• center : [0,0]
square(5);                                  // square 5 x 5
square([2,3]);                              // rectangle 2 x 3
square({size: [2,4], center: true});        // rectangle 2 x 4, centered on both X and Y axis

The CSG library functions can also be used. NOTE: Deprecated in the V2 API

CAG.rectangle({center: [0,0], radius: [5, 10]});
CAG.roundedRectangle({center: [0,0], radius: [10, 50], roundradius: 1, resolution: 4});

### Circle

A two dimensional shape made by drawing a curve that is always the same distance from a center. All points are the same distance from the center.

The following show examples of creating circles. The radius specifies the size. The resolution option determines the number of segments to create in 360 degrees of rotation.

Note: See the start of 2D Primitives for information about the resolution of two dimensional shapes.

Defaults:

• radius : 1
• center : [0,0]
• resolution: defaultResolution2D (32)
let c1 = circle(1)
let c2 = circle({r: 2, fn:5})            // fn = number of segments to approximate the circle
let c3 = circle({r: 3, center: true})

The CSG library functions can also be used. NOTE: Deprecated in the V2 API

let c4 = CAG.circle({center: [0,0], radius: 3, resolution: 32})

### Polygon

A two dimensional shape with straight sides, and the shape is “closed” (all the sides connect up).

The following show examples of creating polygons from a list of points.

Defaults:

• empty
let p1 = polygon([ [0,0],[3,0],[3,3] ])
let p2 = polygon({ points: [ [0,0],[3,0],[3,3] ] })

The CSG library functions can also be used. NOTE: Deprecated in the V2 API

let p3 = CAG.fromPoints([ [0,0],[5,0],[3,5],[0,5] ])