JT Form Change 2.0.1
Copyright (c) 2026 J techno Inc. / 有限会社 Jテクノ

OVERVIEW
========
JT Form Change is an Autodesk Fusion add-in that rebuilds selected BRep faces as quad geometry and converts them into editable Form/T-spline surfaces.

KEY FEATURES
============
• Converts trimmed planar, cylindrical, conical, and freeform surfaces.
• Builds connected Quad Mesh/T-spline geometry from adjacent faces.
• Previews split candidates for narrow or complex regions before conversion.
• Converts one selected region or all candidate regions.
• Evaluates the outline and surface against a specified mesh tolerance.
• Removes only the converted area from the source solid and preserves unselected areas.
• Optionally keeps a hidden copy of the original solid.
• Supports automatic Form handoff, Quad Mesh output, and OBJ export.

SYSTEM REQUIREMENTS
===================
• Autodesk Fusion
• Windows

A macOS build is not provided.

INSTALLATION
============
1. Copy the JTFormChange folder to:
   %APPDATA%\Autodesk\Autodesk Fusion\API\AddIns\JTFormChange
2. Restart Autodesk Fusion.
3. Verify JTFormChange under Utilities > Scripts and Add-Ins.

BASIC WORKFLOW
==============
1. Run JT Form Change.
2. Select one or more BRep faces to convert.
3. Adjust Mesh tolerance if needed. The default is 0.01 mm.
4. Press “1. Calculate and show split positions.” The source geometry is not changed at this stage.
5. Confirm the displayed split positions and candidate regions.
6. For a partial conversion with multiple regions, choose the region to keep.
7. Enable “Keep the source solid” if a hidden source copy is required.
8. Press “3. Convert and open Form.”

When no split is required, all originally selected faces are used automatically. Region selection is also unnecessary when all regions are converted.

PREVIEW DISPLAY
===============
• Orange line: split to be applied.
• Coloured outline: candidate conversion region.
• Heavy outline: currently selected region.
• Yellow line: reference location requiring review.

If the preview does not match the intended range, cancel before changing the source and review the face selection or settings.

BASIC SETTINGS
==============
Mesh tolerance
  Controls how closely the quad geometry follows the source outline and surface. Smaller values may increase mesh density and processing time.

Keep the source solid
  Saves a hidden copy of the solid before conversion. The default is off.

ADVANCED SETTINGS
=================
The default values are suitable for normal use.

• Mesh density method: Use the tolerance method for normal work. Select U/V control only when direct division counts are required.
• Minimum element length: Limits excessive mesh density. The default is 1 mm; zero disables it.
• Maximum element length: Prevents flat areas from becoming too coarse. The default zero disables it.
• Separate surface tolerance: Use when the surface requires a different value from the outline.
• Output format: Choose Form conversion, Quad Mesh output, Fusion Convert Mesh, or OBJ export.
• Open Form after conversion: Starts Form editing after conversion. If Fusion cannot complete the automatic handoff, the Quad Mesh and recovery steps remain available.
• Detached source faces: Choose whether they are stitched, hidden, or shown.
• Detailed support information: Enable only when requested by support.

VERIFYING THE RESULT
====================
JT Form Change produces an approximation of the source BRep. Verify the following as required for the intended use:

• Position of the converted outline against the source edges.
• Surface smoothness and continuity.
• Connectivity between adjacent faces.
• Folded cells, duplicate edges, or excessively thin cells.
• Required dimensions, tolerances, and manufacturing conditions.

While Form remains editable, Fusion's public functions do not provide a continuous maximum-deviation check over the final T-spline surface. Do not treat the reported mesh accuracy as proof of final-surface accuracy; inspect the result with suitable Fusion tools.

IMPORTANT LIMITATIONS
=====================
• Not every trimmed face can be converted into a usable T-spline.
• Holes, slots, singularities, severe necks, and non-manifold geometry may not produce the expected result.
• Save important design data or create a new version before running the add-in.
• Verify the converted result before design, analysis, machining, or manufacturing use.

LICENSE AND TRIAL
=================
• One license covers one user on one device.
• After accepting the EULA and Privacy Policy, each device can use one 72-hour trial.
• The trial does not convert automatically into a paid subscription and does not auto-charge.
• Standard price: JPY 4,990/month or JPY 49,900/year (tax included).
• International standard price: USD 29.90/month or USD 299.00/year.

See the included EULA and Subscription Terms for complete conditions.

SUPPORT
=======
When contacting support, provide:

• JT Form Change version.
• Autodesk Fusion version.
• Windows version.
• Selected faces and settings.
• Reproduction steps.
• Screenshots.
• JTFormChange.log when requested.

Contact:
https://www.j-techno.biz/contact.php
contact@j-techno.biz

Detailed log:
Windows Temp folder\JTFormChange.log

Normal license activation does not transmit Fusion design models, geometry data, or manufacturing data. Providing a model for support is optional.
