1.1.10 Circle

There are three objects we can use to define 3D representations:

• Surface (for polygons) / Circle (special Surface object)

• Volume

• Line

This section will discuss the use of Circle object(s) to represent a 2D surface or 3D volume if thickness parameter is specified.

A Circle object is a convenience object representing a special Surface object. Circle objects can be used to define circular surfaces quicker.

Syntax

<O T="Circle">

.

.

</O>

Elements

Parent elements: Project, Surface, Volume, Line, Section, Shape, Group, Repeat

Child elements: Parameters, Point, Surface, Circle, Shape, Group, Repeat

Parameters

Examples

Example 1

When adding a circle to the project, the default radius is 5 and the default number of segments is 36:

<O N="Sample: Circle" T="Project">

<O N="Circle 2D" T="Circle">

<P N="Radius" V="5" />

</O>

</O>

Increasing Segments value will give a smoother surface:

<O N="Sample: Circle" T="Project">

<O N="Circle 2D" T="Circle">

<P N="Radius" V="5" />

<P N="Segments" V="60" />

</O>

</O>

Example 2

Using Line object to create a circular column:

<O N="Sample: Circle" T="Project">

<O N="Column" T="Line">

<O T="Point" X="0" Y="0" Z="0" />

<O T="Point" X="0" Y="0" Z="20" />

<O T="Section">

<O T="Shape">

<O N="Circle 3D" T="Circle">

<P N="Radius" V="5" />

<P N="Segments" V="20" />

</O>

</O>

</O>

</O>

</O>

Increasing Segments value will give a smoother surface:

<O N="Sample: Circle" T="Project">

<O N="Column" T="Line">

<O T="Point" X="0" Y="0" Z="0" />

<O T="Point" X="0" Y="0" Z="20" />

<O T="Section">

<O T="Shape">

<O N="Circle 3D" T="Circle">

<P N="Radius" V="5" />

<P N="Segments" V="60" />

</O>

</O>

</O>

</O>

</O>

Example 3

Below is a Group object defining the parameters for a circle:

<O T="Group">

<P N="th" V="10" D="Thickness" />

<P N="r" V="5" D="Radius" />

</O>

Example 3.1

Definition for a 3D object with full circular surface:

<O N="Full Circle" T="Circle">

<P N="Thickness" V="th" />

<P N="Radius" V="r" />

</O>

Example 3.2

Definition for a 3D object with semi-circular surface:

<O N="Half Circle" T="Circle" X="r * 2 + 2">

<P N="Thickness" V="th" />

<P N="Radius" V="r" />

<P N="StartAngle" V="0" />

<P N="EndAngle" V="PI" />

</O>

Example 3.3

Definition for a 3D object with quarter circular surface:

<O N="Quarter Circle" T="Circle" X="r * 4 + 4">

<P N="Thickness" V="th" />

<P N="Radius" V="r" />

<P N="StartAngle" V="0" />

<P N="EndAngle" V="PI/2" />

</O>

Example 4

Below is a Group object defining the parameters for an ellipse:

<O T="Group">

<P N="th" V="10" D="Thickness" />

<P N="r" V="5" D="Radius" />

<P N="r2" V="3" D="Radius 2 (for ellipse)" />

</O>

Example 4.1

Definition for a 3D object with full elliptical surface:

<O N="Full Ellipse" T="Circle">

<P N="Thickness" V="th" />

<P N="Radius" V="r" />

<P N="Radius2" V="r2" />

</O>

Example 4.2

Definition for a 3D object with semi-elliptical surface:

<O N="Half Ellipse 1" T="Circle" X="r * 2 + 2">

<P N="Thickness" V="th" />

<P N="Radius" V="r" />

<P N="StartAngle" V="0" />

<P N="EndAngle" V="PI" />

<P N="Radius2" V="r2" />

</O>

Example 4.3

Definition for a 3D object with semi-elliptical surface:

<O N="Half Ellipse 2" T="Circle" X="r * 2 + 2" Y="-r2 * 3 - 3">

<P N="Thickness" V="-th" />

<P N="Radius" V="r" />

<P N="StartAngle" V="PI/2" />

<P N="EndAngle" V="-PI/2" />

<P N="Radius2" V="r2" />

</O>

Example 4.4

Definition for a 3D object with semi-elliptical surface:

<O N="Quarter Ellipse" T="Circle" X="r * 4 + 4">

<P N="Thickness" V="th" />

<P N="Radius" V="r" />

<P N="StartAngle" V="0" />

<P N="EndAngle" V="PI/2" />

<P N="Radius2" V="r2" />

</O>