Create Spline From Coordinates

Create Spline From Coordinates

File: Part_Document_Scripts/Create_Spline_From_Coordinates.py
Version: 1.0
Document Type: Part

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Description

Creates a GSD point set and spline in the active CATPart from arbitrary X Y (or X Y Z) coordinates. Coordinates can be loaded from a .dat, .csv, or .txt file, or pasted directly into a text area in the dialog. Non-numeric header lines and lines beginning with # are silently skipped.

The script creates a geometric set (user-named) containing:

• A Points sub-set with all input points
• A GSD spline (Spline) through all points — open or closed at the user's option

A uniform scale factor can be applied to convert between coordinate units. Settings are persisted between runs.

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Requirements

Requirement	Value
Python	>= 3.10
pycatia	>= 0.8.3
wxPython	Required
Open document	Part

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Usage

1. Open a CATPart document
2. Run the script
3. Choose input mode (File or Paste Text) and supply your coordinates
4. Set the geometric set name, scale factor, close option, and output plane
5. Click OK — a progress bar shows while geometry is created
6. A new geometric set is added to the part containing the point set and spline

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Input Formats

File (.dat / .csv / .txt)

Click Browse to select a coordinate file. Supported formats:

Format	Description
Selig .dat	First line is a text label (skipped), followed by X Y pairs
CSV	Comma-separated X,Y or X,Y,Z values, optional header row
Whitespace	Space- or tab-separated X Y or X Y Z values

Lines beginning with # are treated as comments and skipped. Any line that cannot be parsed as numbers is silently ignored, so header rows require no special handling.

Paste Text

Switch to Paste Text mode and type or paste coordinates directly into the text area. Each line should contain one point:

10.5  0.0
20.3  5.2
35.0  8.1

Columns may be separated by spaces, tabs, or commas.

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Parameters

Parameter	Description	Default
Input mode	File or Paste Text	File
Geometric set name	Name given to the output geometric set	Spline
Scale factor	Uniform multiplier applied to all coordinates	1.0
Close spline	Connect the last point back to the first	Unchecked
Plane	Output plane for 2-D input: XY, XZ, or YZ	XY

Scale Factor

A uniform multiplier applied to all coordinate values:

Value	Effect
1.0	Use raw values as-is (coordinates already in mm)
1000.0	Convert metres → millimetres
25.4	Convert inches → millimetres
0	Same as 1.0 — no scaling

Close Spline

Connects the last point back to the first point to form a closed loop.

• Enable for closed profiles (airfoil cross-sections, pipe profiles, cam lobes)
• Disable for open curves (path guides, camber lines, boundary curves)

Plane (2-D input only)

Determines which 3-D plane the 2-D (X Y) input is placed on:

Plane	Point mapping
XY	(X, Y, 0)
XZ	(X, 0, Y)
YZ	(0, X, Y)

If 3-column (X Y Z) input is supplied, this setting is ignored.

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Dialog Buttons

Button	Action
OK	Validates inputs and creates the spline
Cancel	Exits without creating anything
Reset Defaults	Restores factory default values
Clear Saved	Deletes the saved user presets file
Help	Opens the full in-script user manual

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Output

A geometric set named as specified is created at the top level of the part tree:

<Geometric Set Name>
├── Points
│   ├── Point_001
│   ├── Point_002
│   │   ...
│   └── Point_NNN
└── Spline  (open or closed)

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Settings Persistence

All settings except the raw coordinate data are saved automatically to:

%APPDATA%\pycatia_scripts\Create_Spline_From_Coordinates\user_presets.json

The next time the script runs, your last-used values are pre-filled in the dialog.

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Notes

• At least 3 valid coordinate pairs are required to create a spline
• If 3-D (X Y Z) coordinates are detected in any row, the plane selection is ignored for all rows
• The geometric set can be renamed in the CATIA tree after generation