How to Create a Coordinate Point in CATIA

To create a coordinate point in CATIA, you primarily use the Point command, specifying the X, Y, and Z values. This allows for precise placement of a point in 3D space, either relative to the absolute origin or a user-defined reference point.

Understanding Point Creation by Coordinates

In CATIA, the most common way to define a point using numerical values is through its coordinates. This method is fundamental for precise geometric construction and is accessible across various workbenches like Part Design and Wireframe and Surface Design.

The Point Definition Dialog Box

The core of creating a coordinate point lies within the Point Definition dialog box. Here, you define the type of point and its parameters.

1. Accessing the Command: Navigate to the Wireframe toolbar (in Wireframe and Surface Design workbench) or Sketch-Based Features toolbar (in Part Design workbench) and click the Point icon.
2. Selecting Point Type: In the Point Definition dialog box, ensure Coordinates is selected from the Type dropdown menu. This enables the X, Y, and Z input fields.
3. Inputting Coordinates: Enter the desired numerical values for the X, Y, and Z axes. These values will determine the point's position in 3D space.

Defining the Reference for Coordinates

A critical aspect of creating a coordinate point is understanding its reference. By default, CATIA measures the X, Y, and Z coordinates from its absolute origin (0,0,0). However, for more flexible and contextual design, you can change this reference:

• Absolute Origin (Default): If no reference is selected, your entered coordinates (X, Y, Z) are measured directly from CATIA's global origin point.
• Selected Reference Point: If you do not want to use the absolute origin, you can select an existing point in your part as the Reference in the Point Definition dialog box. When an existing point is selected as the reference, the X, Y, and Z values you input will then be measured relative to that chosen point, making it the local origin for your new coordinate point. This is particularly useful for creating features relative to an existing geometry.

The table below summarizes how the reference selection impacts your coordinate input:

Reference Type	Description
None (Default)	Coordinates are measured from the absolute origin (0,0,0) of the CATIA part.
Selected Point	Coordinates are measured from the selected existing point, which acts as a local origin for the new point.

Step-by-Step Guide to Creating a Coordinate Point

Follow these steps to precisely create a coordinate point in CATIA:

1. Open CATIA and a Part Document: Ensure you are in a suitable workbench, such as Part Design or Wireframe and Surface Design.
2. Activate the Point Command:
   • Go to Insert > Wireframe > Point.
   • Alternatively, locate the Point icon in the Wireframe toolbar.
3. Select 'Coordinates' Type: In the Point Definition dialog box that appears, set the Type dropdown to Coordinates.
4. Enter X, Y, Z Values: Input the numerical values for the X, Y, and Z coordinates in their respective fields.
5. Choose a Reference (Optional but Recommended):
   • By default, the Reference field is empty, meaning the coordinates are relative to the absolute origin.
   • To use a different reference, click the Reference field and then select an existing point from your part in the graphical area. The coordinates you entered will now be relative to this selected point.
6. Preview and Confirm: Click Preview to see the point's location, then click OK to create the point.

Practical Insights and Best Practices

• Precision is Key: When defining points by coordinates, accuracy in your input values is crucial for the overall integrity of your design.
• Coordinate System Awareness: Always be mindful of the active coordinate system (either global or local if a reference point is chosen) to avoid misplacing points.
• Utilize Reference Points: Leverage existing geometry by selecting reference points. This helps maintain design intent and simplifies modifications later on. For instance, if you need a point always 10mm above the center of a specific hole, you can use the hole's center point as a reference.
• Parameterization: In CATIA, points created by coordinates are parametric. You can always double-click the point in the specification tree to modify its coordinates or reference later.
• Visibility: If your point isn't visible, check your Display settings or ensure it's not hidden by other geometry.

Creating points by coordinates is a foundational skill in CATIA, enabling precise modeling and assembly. By understanding how to define coordinates and utilize reference points, you gain powerful control over your 3D geometry. For further learning on CATIA's comprehensive wireframe features, you can explore resources like Dassault Systèmes' official documentation or various online CAD tutorials.