Frozen A-Pose Exporter, a.k.a FrozenAPE 🧊🦍

FrozenAPE is a set of Unity-specific functions and Editor Menus to allow moving a skinned model into a specific pose and exporting the frozen static mesh of that pose into a Wavefront OBJ or FBX file.

This rather experimental package can be used to pose any given character model into an A-Pose (hence this project's name), and export the frozen, static meshes as OBJ files, to allow further modifications, such as re-skinning, in another DCC tool.

The whole picture is to simplify the workload for Technical Artists when faced to recycling models to other games/engines that require skinning to a particular rig. The closest use-case would be to transform a character model to A-Pose, freeze and export as OBJ, and then reskin the model for e.g. Roblox.

🔧 Building and Running

Add the 2 registries as described below, followed by the dependency on com.kagekirin.frozenape.

Then follow the project configuration described by Cysharp's Csproj Modifier and add (copy) the LangVersion.props from this repo to the 'Addition Project Imports'.

🔨 Add the Project

Due to some dependencies, this projects requires adding the following registries to Unity:

• OpenUPM (which hosts a Unity dependency)
• Unity NuGet (which hosts a C# dependency)

Add OpenUPM registry

The following registry must be added to Unity's manifest.json .scopedRegistries[]:

{
    "name": "OpenUPM",
    "url": "https://package.openupm.com",
    "scopes": [
        "com.cysharp",
        "com.kagekirin"
    ]
}

Add Unity NuGet registry

The following registry must be added to Unity's manifest.json .scopedRegistries[]:

{
    "name": "Unity NuGet",
    "url": "https://unitynuget-registry.azurewebsites.net",
    "scopes": [
        "org.nuget"
    ]
}

Add package to project

Add com.kagekirin.frozenape to the manifest.json .dependencies{}:

"dependencies": {
    "com.kagekirin.frozenape": "0.0.7",
}

⚡ Usage guide

▶ Running from Editor

FrozenAPE adds a few menu/context menu entries:

• FrozenAPE > Export as Wavefront OBJ: exports all the meshes from the currently selected GameObject or the currently selected Mesh as Wavefront|OBJ (aka Maya OBJ) file(s). CAVEAT: Since OBJ does not support skinning data per-se, the skinning data associated with SkinnedMeshRenderer will not be exported.
• FrozenAPE > Create Sample Pose JSON: creates a sample pose.json to allow manual modification.
• FrozenAPE > Pose From JSON: loads a JSON file and applies the pose data to the currently selected GameObject.
• FrozenAPE > Freeze Current Pose: creates a copy of the currently select GameObject, where every mesh has been replaced by a (baked) static mesh, frozen at the current pose.

Given a manually prepaired pose.json, the workflow to export the frozen pose would be:

1. FrozenAPE > Pose From JSON
2. FrozenAPE > Freeze Current Pose
3. FrozenAPE > Export as Wavefront OBJ

▶ Calling from code

The runtime consists of 4 interfaces and their respective implementations:

• IWavefrontOBJWriter.WriteOBJ() creates the OBJ mesh data (text) from a given mesh and its materials
• IWavefrontMTLWriter.WriteMTL() creates the OBJ material library (MTL file, text) from the materials associated with a mesh.
• IRigPuppeteer.Pose() moves the provided Transforms (from GameObject.GetComponentsInChildren<Transform>(true)) into the pose specified by a set of PosedBones.
• IPoseFreezer.Freeze() returns the frozen (in Unity terms: baked) meshes and their respective materials from a GameObject, respectively a SkinnedMeshRenderer.

NOTE: registering the interfaces and their implementations with a dependency injection framework allows to inject the implementations at runtime.

🤝 Collaborate with My Project

Please refer to COLLABORATION.md