SpeedUpUtils

SpeedUpUtils was inspired by the Double Mirror workflow in SolidWorks, especially after watching CAD modeling competition videos.

The broader vision is to build a set of utility tools for Autodesk Fusion that help designers spend less time modeling and more time thinking.

Right now, the add-in includes one command: Double Mirror, which is the default command when the add-in launches.

Demo

How it works

The tool supports 5 entity types as input to compute/use as your mirror plane: Sketch Lines, Construction Axes, BRepEdges, BRepFaces and Construction Planes.

Internally, the add-in builds construction planes from the selected lines/axes/planar surfaces, or it uses existing construction planes. It uses 3D vector methods from Fusion API to convert lines/axes to planes.

Once that's done, it uses the mirror command twice to build the final output.

How to install

The installation pattern follows the standard Fusion add-in layout used by Autodesk samples. See the official support article here.

0. Download the DLL from GitHub Actions in this repo, and manifest (Or build from source)

1. Place the add-in in Fusion's AddIns folder

• Windows: %APPDATA%\Autodesk\Autodesk Fusion 360\API\AddIns\

• macOS (web install): ~/Library/Application Support/Autodesk/Autodesk Fusion 360/API/AddIns/

Create a folder named SpeedUpUtils under the AddIns directory.

2. Ensure required files are in the SpeedUpUtils folder

At minimum, keep these files together inside the folder:

• SpeedUpUtils.manifest

• SpeedUpUtils.dll (Windows build output)

3. Start the add-in from Fusion

1. Launch Fusion.

2. Open Utilities -> Scripts and Add-Ins.

3. Go to the Add-Ins tab.

4. Select SpeedUpUtils and click Run.

5. Optional: enable Run on Startup if you want it loaded automatically.

If Fusion is already open when you copy/update files, restart Fusion before checking the add-in list.

How to use

You need to start with one body, and have the body's component activated in your Design workspace.

1. Launch the tool (From the Scripts & Add-Ins menu, shortcut: Shift + S)

2. Select your body

3. Select your mirror planes/lines

   • The tool supports selection of Sketch Lines, Construction Axes, BRepEdges, BRepFaces and Construction Planes.

   • Selections must be the same type of entity (i.e. both construction planes or both sketch lines)

4. Press OK

How to build

The build process documented below is for Windows only. I don't know how to build on MacOS.

Prerequisites:

1. Windows SDK

2. MSVC Toolset v143 (Build Tools for VS 17.x)

Build steps

1. Navigate to %AppData%\Autodesk\Autodesk Fusion 360\API\AddIns\

2. Clone this repo

3. Open the project directory in Developer Command Prompt for VS 2022

4. Run msbuild .\SpeedUpUtils.vcxproj /p:Configuration=Release /p:Platform=x64

5. The compiled .dll binary will automatically be copied from Release (or Debug) folder to the project root folder

   • Fusion will search recursively for add-ins in the AddIns folder, and it will load the .dll found in the project root folder.

Troubleshooting failed builds

1. The add-in does not show up in Fusion Add-ins menu

   • Fusion expects the manifest and .dll files in the project folder. Make sure these items are in the project folder

   • Also make sure that the folder is located in the folder specified in Step 1 of Build Steps.

2. Compiler can't locate Fusion API headers

   • The MSVC project configurations are set to look for headers in $(APPDATA)/Autodesk/Autodesk Fusion 360/API/CPP/include and libraries in $(APPDATA)/Autodesk/Autodesk Fusion 360/API/CPP/lib.

   • The API headers will be automatically installed if you already have an installation of Autodesk Fusion.

   • Make sure both folders exist and include the required libs (core.lib, fusion.lib, cam.lib). The CI workflow validates these same dependencies.

3. Can't complete the xcopy command after compilation

   • The .dll file in project root folder is in use and it can't be overwritten. Stop the add-in in Fusion.

Limitations

• The tool works with 3D BRep body only. You cannot select more than one solid body.

• Working across components is not supported.

• The operation for the mirror command is hardcoded to "Join"

  • It might give you warnings in your timeline if you use it to create 4 bodies instead of just one joined body

• As of now (planned for future work):

  • No button mapped to the Command Ribbon of Fusion UI.

  • No preview before confirmation.

  • No grouped timeline items.

GitHub Actions: Build DLL on Push

This repository includes a workflow at .github/workflows/build-dll.yml that builds SpeedUpUtils.vcxproj with MSBuild on windows-latest and uploads the resulting DLL as an artifact.

SDK source

By default, the workflow pulls the Fusion C++ SDK from Autodesk's official Fusion API reference repository at a pinned commit:

• Repository: AutodeskFusion360/FusionAPIReference

• Folder: Fusion_API_CPP_Reference

Optional override

If you prefer to provide your own SDK package, add a repository secret named FUSION_CPP_SDK_ZIP_URL and point it to a ZIP file containing:

- `include/`
- `lib/`

The workflow maps this SDK to the path expected by the project:

%APPDATA%/Autodesk/Autodesk Fusion 360/API/CPP

Result

On each push or pull request, GitHub Actions will:

1. Set up MSBuild on Windows.

2. Download and validate the Fusion C++ SDK.

3. Build the Release x64 DLL.

4. Upload SpeedUpUtils.dll and SpeedUpUtils.dll.sha256 as downloadable artifacts.

You can verify the downloaded DLL with PowerShell:

Get-FileHash .\SpeedUpUtils.dll -Algorithm SHA256

Compare the Hash value with the value in SpeedUpUtils.dll.sha256.