[Grasshopper] How to use Arc to create arcs

This article explains how to use Arc to create arcs.

On the Grasshopper, it is represented by either of the two above.

Creating an arc

Arc can be used to create a circular arc.

Enter the position information of the location of the center of the arc and the plane in the Arc(P).

If no information is entered, the arc is created at the origin position of 0,0,0.

In this case, the coordinate information of 100,100,0 is entered.

Enter a numerical value for the radius in the Arc(R).

This time, 50 is entered.

In the Arc(A), input the numerical value of the radian of the angle (arc degree method) in the domain range.

This time, a range of 0~Pi is created by entering 0 To Pi.

As you can see, an arc with a radius of 50 in the range 0~Pi was created at coordinates 100,100,0.

Components used: (1) YZ Plane (2) Arc

In the previous example, we specified coordinates for the Arc(P), but this time we will connect the YZ Plane.

As you can see, an arc is created in the specified plane.

Recommended Angle Specification Method

Two recommended methods for specifying angles in Arc are described below.

Create a domain range with Construct Domain

Components used: (1) Pi (2) Construct Domain (3) Arc

The first method is to create a domain range with Construct Domain.

With this method, you can easily change the arc range by changing the Number Slider value.

First, create two Number Sliders with numerical values ranging from 0 to 2.0.

In this case, we set them to 0 and 2.0.

Then, connect each Number Slider to Pi.

This creates a number that is multiplied by Pi.

Then, connect the two Pi to the Construct Domain(A and B), respectively.

In this case, 0 and 2.0 Pi are connected, so a domain range of 0~2Π is created.

Finally, we connect Construct Domain to the Arc(A).

Since 0~2Π is specified, a circle is created.

We changed the values to 1.0 and 2.0 and set the domain range to Pi~2.0Pi.

Then it easily changed to a semicircular arc.

I changed the values to 1.0 and 1.5 and set the domain range to Pi~1.5Pi.

Then I could easily create different arcs.

Thus, creating a domain range with Construct Domain eliminates the need to specify the domain range by letter each time. 

Creating a Domain Range by Degrees

Components used: (1) Construct Domain (2) Radians (3) Arc

The second method is to create a domain range by degrees.

Under normal conditions, you need to specify a number in radians (arc degree method).

However, Radians allows you to specify angles in degrees (degree method).

Create two Number Sliders that can be changed from 0~360.

In this case, we set them to 0 and 270.

Then, connect the two Number Sliders to the Construct Domain(A and B), respectively.

Then, connect Construct Domain to Radians.

This converts from degrees to radians.

Finally, Radians is connected to the Arc(A).

An arc is then created.

In this way, angles can also be specified in degrees.

Output Data

Additional components: (1) Circular Arc (2) Curve

The Arc(A) outputs the curve data of a circular arc.

The Arc(L) outputs the numerical value of the arc length.

List of Grasshopper articles using Arc component↓

Arc

Arcコンポーネントを使用しているグラスホッパー記事一覧です。List of Grasshopper articles using Arc component

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