[CIM/Infor-Base] Understanding the Constraint Entity(Plane)

Question 

Please describe the Constraint Plane.

Answer 

Constraint Plane is alignment variable It determines the start and end of the Main Path and its scope.

In CIM, there is an object called Constraint Entity that is responsible for only the constraint of the model apart from modeling that determines the shape.

This structure captures the common constraint information of various objects created during modeling. It is advantageous to control the model because it can be integrated and managed by linking to one Constraint Entity. Therefore, in order for CIM's alignment-based modeling to work as intended by users, an understanding of Constraint Entity is required.

The Constraint Entity of CIM is as follows, and this FAQ deals with the Constraint Plane.

<Type of Constraint Entity>

Expression Entity linked to Constraint Path property is only applicable to Path Linked Entity created by
Curve Library Mode   : Expression Entity > Path Linked function or
Assembly Unit Mode : Expression Entity > Path Linked function.

Similarly, Expression Entity linked to Constraint Point properties is a library created as
Single Point or Multi-Points in Point Library Mode,
Curve Library Mode: Expression Entity > Point Linked function, or
Assembly Unit Mode : Applicable only to Point Linked Entity created by Expression Entity > Point Linked function .

Objects that are correlated with the Constraint Plane are as follows.

Constraint Plane

Property of Constraint Plane

Difference in the result of alignment assignment according to the Alignment setting (Ratio/Distance)

Objects affected by Constraint Plane

Figure 1. Objects affected by Constraint Plane

Constraint Plane is created on the Default Constraint Path and behaves in Layout according to the rules defined in Location and Alignment that have properties.

Objects which affect Constraint Plane

Figure 2. Objects which affect Constraint Plane

If you look at Figure 2, you can see that the Start / End Point of the Main Path Property has information with each constraint plane selected at the time of creation.

Therefore, the two objects have a dependency relationship, and the X-coordinate value of the Start / End Point of the Main Path is determined according to the Location (X-coordinate value) of the Constraint Plane.
(The two values ​​match.)

When the Path Linked Entity assigned to the Main Path or the arranged Point Linked Entity object through the above is assigned to the Layout It has been confirmed that the Constraint Plane determines the Start / End area to be created in which range.

We summarize the above with a simple example model for better understanding.

Figure 3. Plane Position : 7.5m

Figure 4-1. Path Linked Entity assigned to Main Path (Perspective View)	Figure 4-2. Path Linked Entity assigned to Main Path (Side View)

Figure 5. Plane Position : 5.0m

Figure 6-1. Change End Plane Location (7.5m > 5m) (Perspective View)	Figure 6-2. Change End Plane Location (7.5m > 5m) (Side View)

The above case is an example of updating the model by modifying the location property of the end plane after creating a pipe-shaped Path Linked Entity on the main path connecting the constraint plane of each location 2.5m/7.5m.

CIM checks the Main Path created by referring to the Plane as in the case and the Location and Alignment properties of all objects assigned to it.
It is useful for alignment and relationship theorem because it is batch managed in one plane.

Below is an example of changing the branch of PSC Box Girder using Constraint Plane.

Figure 7. Change of branch configuration by changing the location of the plane