AssetStudio for macOS

None of this repo, the tool, nor the repo owner is affiliated with, or sponsored or authorized by, Unity Technologies or its affiliates.

This is a macOS port of Perfare/AssetStudio, a tool for exploring, extracting and exporting Unity assets and AssetBundles. The original project is Windows-only (WinForms). This fork adds a native macOS application built with .NET MAUI / Mac Catalyst, on top of the same parsing/export engine from the original repo.

All credit for the core asset-parsing engine, the TypeTree/SerializedFile format handling, and the texture/FBX export pipeline goes to Perfare and the original contributors. This fork's job was porting that engine to run natively on macOS and building a new UI for it — the parsing logic itself (AssetStudio/, AssetStudioUtility/) is unchanged except for a couple of upstream bug fixes described below.

What's different in this fork

• AssetStudio.Maui — a new native macOS app (Mac Catalyst), replacing the Windows WinForms GUI for Mac users.
• AssetStudioCore — a new UI-agnostic port of the original AssetStudioGUI/Studio.cs facade, with all WinForms types (TreeNode, ListViewItem, MessageBox, Properties.Settings, etc.) replaced by plain, platform-neutral equivalents so the same engine can drive any UI.
• Native decoder/exporter libraries (Texture2DDecoderNative, AssetStudioFBXNative) gained CMakeLists.txt files to build as macOS universal (arm64 + x86_64) dylibs — the original repo only ships Visual Studio project files for these.
• Real parsing/interop bugs found and fixed while building this port (see Notable fixes).
• The left panel has three tabs mirroring the original Windows GUI's layout:
  • Asset List — the flat, filterable, sortable list, with Name / Container / Type / PathID / Size columns. Columns are resizable (drag the column border) and have visible grid lines, matching the original ListView.
  • Scene Hierarchy — a GameObject tree view (parent/child nesting from each object's Transform), expand/collapse per node.
  • Asset Classes — the list of TypeTree class definitions found in the loaded file(s) (Name + ID); selecting one shows its full field layout in the Dump tab.
• The right (preview) panel has two tabs:
  • Visual Preview — the image / interactive 3D viewer / audio player / generic placeholder, depending on the selected asset's type.
  • Dump — the asset's TypeTree field dump as text, available for every asset type (including ones with a visual preview, e.g. a Mesh's raw fields alongside its 3D view).
• macOS-specific app features beyond the original Windows GUI:
  • Texture preview zoom via scroll wheel/trackpad or +/- buttons, with proper clipping and scrollbars when zoomed past the preview area.
  • An interactive 3D mesh viewer (rotate/zoom with the mouse) for Mesh assets, built with three.js, in addition to the existing OBJ export, with a wireframe toggle.
  • Mesh → FBX export (not just OBJ).
  • A generic 3D placeholder preview for Shader assets — see limitations below for why it's a placeholder and not the real shader.
  • AudioClip playback preview (Play/Stop) via the FMOD Engine and native AVAudioPlayer — see Requirements for the separate FMOD download this needs.

Project structure

Project	Purpose	Platform
AssetStudio	Core parsing engine (SerializedFile/TypeTree, asset classes)	net8.0, cross-platform
AssetStudioUtility	Export helpers (texture/FBX/audio conversion)	net8.0, cross-platform
AssetStudio.PInvoke	Cross-platform native library loader (dlopen/LoadLibrary)	net8.0, cross-platform
AssetStudioFBXWrapper	P/Invoke bindings to AssetStudioFBXNative	net8.0, cross-platform
Texture2DDecoderWrapper	P/Invoke bindings to Texture2DDecoderNative	net8.0, cross-platform
Texture2DDecoderNative	Native texture decoders (ASTC/ETC/PVRTC/crunch/...)	C++, now builds via CMake for macOS
AssetStudioFBXNative	Native FBX export, links the Autodesk FBX SDK	C++, now builds via CMake for macOS
AssetStudioCore	New. UI-agnostic facade used by the macOS app	net8.0
AssetStudio.Maui	New. The macOS app	net10.0-maccatalyst
AssetStudioGUI	Original Windows WinForms app	net8.0-windows, untouched

Requirements

To build this from source on macOS you'll need:

• macOS with Xcode 26.4+ and the command line tools installed (xcode-select --install). The .NET 10 MacCatalyst SDK's linker step requires the Xcode 26.4 MacCatalyst SDK or newer for Release-configuration builds; Debug builds are more lenient about the exact version. After installing/upgrading Xcode, run xcodebuild -runFirstLaunch once to finish setting up its command-line components.
• .NET 10 SDK.
• The .NET MAUI workload:

  dotnet workload install maui
  

• CMake 3.16+ to build the native libraries (brew install cmake, or download from cmake.org if you don't use Homebrew).
• Autodesk FBX SDK 2020.3.9 for macOS — only required if you want FBX export/preview to work. It's a free download but requires registering an Autodesk account; it cannot be bundled in this repo. The app and every other feature (texture/audio/mesh-OBJ export, the 3D mesh/shader viewer, etc.) work fine without it — without the FBX SDK, just skip building AssetStudioFBXNative and FBX export will simply be unavailable at runtime instead of failing to build.
• FMOD Engine for macOS — only required for the AudioClip playback preview (Play/Stop button). Same situation as the FBX SDK: it's a free download requiring registration, proprietary, and not bundled in this repo. Without it, every other feature works fine — AudioClip assets just show the generic placeholder preview instead of a Play button (export still works independently of this). AssetStudio.Maui.csproj looks for it at /Applications/FMOD Engine/api/core/lib/libfmod.dylib (the default install location for the "FMOD Engine" — not "FMOD Studio" — macOS package) and copies it into the app bundle automatically if present.
• three.js (bundled) — the 3D viewer ships a local copy of three.js r128 and its classic OrbitControls.js under AssetStudio.Maui/Resources/Raw/threejs/ so the app works without a network connection. No separate install needed; see Acknowledgments for license/credit.

Building

1. Clone the repo:

   git clone https://github.com/lforte/AssetStudio-macOS.git
   cd AssetStudio-macOS
   

2. Build the native libraries as universal (arm64 + x86_64) dylibs:

   cmake -B Texture2DDecoderNative/build -S Texture2DDecoderNative \
         -DCMAKE_BUILD_TYPE=Release -DCMAKE_OSX_ARCHITECTURES="arm64;x86_64"
   cmake --build Texture2DDecoderNative/build --config Release
   

   If you installed the FBX SDK (see Requirements), also build:

   cmake -B AssetStudioFBXNative/build -S AssetStudioFBXNative \
         -DCMAKE_BUILD_TYPE=Release -DCMAKE_OSX_ARCHITECTURES="arm64;x86_64"
   cmake --build AssetStudioFBXNative/build --config Release
   

   By default AssetStudioFBXNative/CMakeLists.txt looks for the SDK at /Applications/Autodesk/FBX SDK/2020.3.9. If yours is elsewhere, pass -DFBXSDK_ROOT=/path/to/sdk to the first cmake command above.

   AssetStudio.Maui.csproj automatically copies whichever of these dylibs it finds into the app bundle at build time — you don't need to copy them manually.

3. Build and run the app:

   cd AssetStudio.Maui
   dotnet build -t:Run -f net10.0-maccatalyst
   

   or open the solution in an IDE that supports .NET MAUI (Visual Studio 2022+, VS Code with the MAUI extension, JetBrains Rider) and run the AssetStudio.Maui target.

Releases

See CHANGELOG.md for the full release history since v1.0.0.

.github/workflows/release.yml builds the app and publishes it as a GitHub Release automatically whenever a v* tag is pushed:

git tag -a v1.0.1 -m "v1.0.1"
git push origin v1.0.1

It can also be run on demand from the Actions tab (workflow_dispatch) without creating a release, to sanity-check that the build still works. Note that CI-built releases don't include FBX export or AudioClip playback preview, since the proprietary FBX SDK and FMOD Engine aren't available on GitHub-hosted runners — see the comments at the top of that workflow file for details. The workflow runs on the macos-26 runner image (Xcode 26.5), which the .NET 10 MacCatalyst Release build needs — see Requirements.

Starting with v1.3.0, each GitHub Release has two downloads: the CI build above (AssetStudio.Maui-<version>-macOS.zip) and a locally-built Universal build (AssetStudio.Maui-<version>-macOS-Universal.zip) with the FBX SDK and FMOD Engine installed, so it includes FBX export and AudioClip playback preview on top of everything else. Pick whichever matches what you need — see each release's notes for details.

Usage

• Open File(s) loads one or more Unity asset/AssetBundle files. The status bar shows how many assets were found.
• The left panel has three tabs:
  • Asset List — filter with the search box; sort by clicking any column header (Name/Container/Type/PathID/Size), click again to reverse. Drag a column's right edge to resize it.
  • Scene Hierarchy — click a row to expand/collapse its children (▶/▼) and, for GameObject rows, show that object's field dump in the Dump tab.
  • Asset Classes — click an entry to show its full TypeTree field layout in the Dump tab.
• The right panel has two tabs, independent of which left-panel tab is active:
  • Visual Preview:
    • Texture2D / Sprite — the decoded image. Zoom with the scroll wheel/trackpad or the +/- buttons (bottom-right); the preview area clips and scrolls when zoomed past its bounds.
    • Mesh — an interactive 3D viewer (drag to rotate, scroll to zoom), with a Wireframe toggle.
    • Shader — a generic shaded-sphere 3D placeholder (see limitation below), also with a Wireframe toggle.
    • AudioClip — a Play/Stop button (requires the FMOD Engine — see Requirements).
    • Everything else — the generic placeholder image.
  • Dump — the selected asset's field dump as text (from its TypeTree, when present), for any asset type.
• Export Selected / Export All write the converted assets (PNG/TGA textures, OBJ+FBX meshes, WAV/MP3 audio, JSON MonoBehaviours, etc.) to a folder you choose.

Shader export and preview limitations

Unity strips shader source out of built players and AssetBundles — only compiled GPU bytecode (DXBC/SPIR-V/Metal, depending on target platform) survives. What gets exported as .shader is a disassembly of that bytecode formatted to look like ShaderLab/HLSL, for human inspection — it is not valid, recompilable shader source. That's also why it won't re-import cleanly into a Unity project (you'll see a pink/error material): there's no way to recover the original source from compiled bytecode without a project-scale decompiler, which is out of scope here.

For the same reason, the 3D "Show 3D Preview" option for shaders does not run the actual shader — it renders a generic sphere whose color/metalness/roughness are derived from the shader's own declared default property values (or a deterministic color derived from its name, if no useful default exists), just so different shaders are visually distinguishable while browsing.

Notable fixes (upstreamed from this port)

While building this port and testing against real-world AssetBundles, two parsing bugs in the original engine surfaced and were fixed (these aren't macOS-specific and apply equally to the original Windows app):

• Texture2D (Unity 2022.2+): a missing m_MipmapLimitGroupName field read caused all subsequent texture data to be misaligned, corrupting decoded textures.
• Shader/SerializedProgram (Unity 2022.1+): two missing fields (m_PlayerSubPrograms, m_ParameterBlobIndices, added by Unity's player-data-separation feature) caused shader parsing to read garbage data, manifesting as 20-60 second parse times per shader object.

Two more bugs surfaced specifically while wiring up AudioClip playback against a current (2.03.14) FMOD Engine download — these are fixed only for the macOS path, since the bundled Windows fmod.dll is the much older 1.07.16 and the original Windows call is left untouched to avoid any risk of regressing it:

• FMOD.Factory.System_Create was missing the headerversion argument that FMOD_System_Create expects — it was calling a 1-argument overload against a native function that takes 2, which FMOD 2.x rejects outright with ERR_HEADER_MISMATCH.
• FMOD.VERSION.number was hardcoded to 0x00010716 (FMOD 1.07.16); the macOS path now sets it to 0x00020314 to match the FMOD Engine version Apple/ARM64 users currently download from fmod.com.

Roadmap

Planned/possible improvements for future versions, roughly in priority order:

Build & distribution

• Upgrade to Xcode 26.4 so Release-configuration builds work — done as of Xcode 26.5; Release builds work locally now (run xcodebuild -runFirstLaunch after upgrading Xcode if you hit an actool/ibtoold plugin-load error).
• Get the CI release workflow building again — done; macos-latest's newest Xcode (26.3, macOS SDK 26.2) was too old for the same 26.4+ requirement above, so release.yml now runs on the macos-26 image and selects its Xcode 26.5 directly. Verified end-to-end with the v1.3.0 release.
• Code-sign with a Developer ID and notarize releases, so macOS Gatekeeper doesn't block first launch.
• Build AssetStudioFBXNative on a self-hosted CI runner with the FBX SDK installed, so automated releases include FBX export (currently only local builds do — see release.yml).

Feature parity with the original Windows GUI

• A Scene Hierarchy / GameObject tree view — done; see the Scene Hierarchy tab, plus the new Asset Classes tab and Container/PathID/Size columns on the Asset List tab.
• AudioClip playback preview — done via the FMOD Engine + AVAudioPlayer; verified end-to-end (Play/Stop and export) against real AudioClip-bearing AssetBundles as of v1.4.0.
• A search box for the Scene Hierarchy tab (the original GUI's treeSearch) — the Mac app's tree has no search yet, only the Asset List tab does.
• An assembly-directory picker for MonoBehaviour export, including the Il2CppDumper dummy-DLL workflow.
• An export-options panel (scale factor, FBX version, eulerFilter, etc.) — currently uses ExportSettings defaults with no UI to change them.
• Multi-select in the Asset List (Shift-click to select a range) so Export Selected can export more than one asset at a time, matching the original ListView's multi-selection behavior.

Polish

• Remove the on-screen debug overlay in the 3D viewer — done; the diagnostic #debug div/debugLog()/window.onerror leftover from chasing a WebView data-transfer bug has been removed from MeshViewerHtml.cs.
• Add a wireframe-toggle button in the UI — done; a "Wireframe" button appears top-right of the 3D viewer for both Mesh previews and the Shader 3D placeholder preview.
• Revisit 3D viewer performance for very large meshes — it currently rebuilds and reloads the whole WebView page per selection.
• The Asset List's Name column isn't resizable (only Container/Type/PathID/Size are) — it currently absorbs all remaining width by design, but a drag handle would match the original GUI more closely.
• Replace the deprecated AVAudioPlayer(NSData, string, out NSError) constructor used for audio playback with the recommended non-deprecated equivalent.
• Clear the Asset List, Scene Hierarchy, and Asset Classes tabs when opening a new file/folder — they currently keep showing the previously loaded file's entries until the new data replaces them.
• Only re-filter the Asset List when the user presses Enter in the search box, instead of on every keystroke — on files with a lot of assets, filtering on each keypress makes typing feel slow.

Robustness

• Audit other asset classes for the same kind of version-specific missing-field bugs found in Texture2D and Shader (see Notable fixes), especially for Unity versions newer than 2022.1 (the original project's documented support ceiling).

Acknowledgments

• Perfare/AssetStudio — the original project this is ported from. This fork would not exist without it.
• Ishotihadus/mikunyan, BinomialLLC/crunch, Unity-Technologies/crunch — texture decoder references used by Texture2DDecoderNative (inherited from upstream).
• three.js (MIT) and its OrbitControls addon — power the interactive 3D viewer.
• Autodesk FBX SDK — used by AssetStudioFBXNative for FBX export; proprietary, not redistributed in this repo.
• FMOD Engine by Firelight Technologies — used for AudioClip decoding/playback preview; proprietary, not redistributed in this repo.

License

MIT — see LICENSE. Original copyright retained from Radu and Perfare; macOS port additions are licensed the same way.