## Question

**Is it possible to control the length of an object, such as the height of a column, with a parameter?**

## Answer

**Multi-Points Linked Entity allows you to control the length of an object.**

In Point Library Mode, a Multi-Points Linked Entity defines each Geometry Vertex of an object by constraining them to individual Constraint Points.

Here, Geometry refers to the shape information of an object, and it determines the object's overall shape.

In other words, through the process of defining a Multi-Points Linked Entity, Geometry Vertex of an object can be constrained to different Constraint Points, and these constrained Geometry Vertex can be used to control the shape of the object through changes in the Constraint Point coordinates using the Multi-Points Linked Entity.

Figure 1. Shape change according to Geometry Vertex

**The order of defining a Multi-Points Linked Entity is as follows**

** **

1. Select the object.

2. Select the Default Constraint Point.

The Default Constraint Point constrains all Geometry Vertices that are not individually

matched to other Constraint Points.

3. Match Other Constraint Points and Geometry Vertices individually and add them. Geometry Vertices that are not matched with Other Constraint Points are constrained to the Default Constraint Point.

After defining coordinate parameters, if you enter the defined parameters

into the Constraint Point coordinate property, you can control the shape through the parameters.

Let's take the cuboid model below as an example.

**Step-1**

I want to create a model that can freely move the axis of a cuboid and transform its shape as desired.

**Step-2**

To achieve this, I need two points that can control the ends of the axes.

To do this, I will select [Point Library] > [Point] from the top menu to create a Constraint Point at each end.

**Step-3**

Once created, I will use the [Multi-Points Linked Entity] function to constrain each end vertex of the cuboid model to the two previously created Constraint Points.

When I select [Point Library] > [Multi-Points] from the top menu, the following window will appear.

**Step-4**

**Multi-Points Linked Entity Settings**

Select Target

: Select the object to constrain. In this example, I will select the cuboid.

Default Constraint Point

: Select the base Constraint Point. Any points not assigned to a Constraint Point will be constrained to this point.

In this example, I will select the Constraint Point created at the origin.

Other Constraint Point

: Select each Vertex of the object to be constrained to the respective Constraint Point previously created.

After selecting the Constraint Point and the corresponding Vertex, click on "Add" to add the constraint.

**Step-5**

After completing the constraints, create parameters to control the coordinates of the vertex.

To create a parameter for controlling the Vertex coordinates, go to the top menu and select

[Point Library] > [Parameter] to open the parameter editing window.

In the example, we created a parameter named 'Y-coordinate'. It's important to note that the parameter type should be set to [Coordinate] so that it can be selected from the Vertex coordinate values.

**Step-6**

After setting up the Coordinate parameter, you can link the axis-specific coordinate values of the selected Constraint Point to the parameter you created earlier.

After completing the linkage, we need to verify that the parameter values can be changed properly.

Coordinate Parameter = 0 m (Top View) | Coordinate Parameter = 2 m (Top View) |

For reference, if you check the [Keep Section Plane] option in the model options, the orientation of the cross-section will be maintained even if the model axis is tilted.

Using the previous model as an example, when you follow the same process with this option checked, you can obtain the following result.

Coordination Parameter = 2 m, Keep Section Plane (Top View)