islandmed/SculptForge

What SculptForge is

SculptForge is a free, GPL-3.0 digital sculpting application aimed at VFX, animation and game artists who want a ZBrush-style workflow without a subscription. It runs natively on Windows, macOS and Linux, offers the familiar brush set, masking, polygroups, SubTools, Polypaint and Gizmo 3D posing, and carries models through to game and animation pipelines instead of stopping at export.

The pipeline side is the practical differentiator: undoable sculpt layers that act as blend shapes, one-click LOD chains with blend shapes preserved at every level, Send to Unreal (Ctrl+U) into a running Editor on the same machine or the network without a plugin, and a Blender 4.2+ bridge add-on that round-trips objects while keeping transforms, materials and modifiers. Export formats include FBX (binary 7.4, LOD groups, blend shapes), glTF/GLB with morph targets, OpenUSD USDA/USDZ with UsdSkel blend shapes, OBJ, PLY and STL.

AI is included at no cost: Brush Lab turns a text description into a brush recipe, and image-to-3D or text-to-3D produces a remeshed, sculptable model. By default these use an open model hosted by Pollinations.ai or the public Hugging Face demos of Hunyuan3D, TRELLIS.2 and Stable Fast 3D; you can instead point them at your own Ollama or LM Studio models, a ComfyUI workflow, or paid fal.ai and Meshy keys. Gaussian splat capture import and conversion, an MCP server for AI agents, and a headless sculptforge-cli cover pipeline automation.

The intended user is an artist already comfortable with ZBrush conventions, or a studio that needs Linux support and scriptable asset processing. The project describes itself as an early release (v0.8), tested on every commit.

Quick start

1. Install a build. Direct downloads: Windows installer, macOS DMG, Linux AppImage; the install directory lists .deb, .rpm, ARM64, portable zip and Arch options. Or install with one command:

   # macOS / Linux
   curl -fsSL https://raw.githubusercontent.com/islandmed/SculptForge/main/install/install.sh | sh
   

   # Windows (PowerShell)
   irm https://raw.githubusercontent.com/islandmed/SculptForge/main/install/install.ps1 | iex
   

2. First launch: builds are not code-signed, so on macOS right-click the app and choose Open; on Windows, if SmartScreen appears, choose More info → Run anyway.

3. Get oriented: open Help > User Guide (Shift+F1) for the searchable manual, and F1 for the controls list. From ZBrush, bring models in via GoZ, OBJ, FBX or GLB; ZBrush's .ZTL/.ZPR files are not read directly, but the ZTool Export plug-in converts a ZTool library once so SculptForge can open the .ZTL files.

4. Sculpt: left-drag to sculpt, Alt to subtract, Shift to smooth, Ctrl to paint mask, Ctrl+Shift to isolate or hide a polygroup. Save with .sfproj projects, export GLB with Ctrl+E, or send to Unreal with Ctrl+U.

5. Optional headless check that the tool works, using the CLI (place rock.obj in the working directory first):

   sculptforge-cli -c 'open path=rock.obj; export_lods path=out/rock.glb levels=4 ratio=0.5'
   

   The result is out/rock.glb containing a four-level LOD chain. Run sculptforge-cli --list for all commands; --mcp exposes them to MCP clients such as Claude Code.

Build from source

Requirements are CMake 3.24+ and a C++20 compiler (GCC 11+, Clang 14+, Xcode 15+ or Visual Studio 2022); Dear ImGui, GLM and SDL3 are fetched automatically. On Linux, install the toolchain and X11/Wayland/GL/curl headers first:

sudo ./packaging/linux/install-build-deps.sh
cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build --parallel
ctest --test-dir build --output-on-failure
./build/sculptforge

The binary path differs by platform: build\Release\sculptforge.exe on Windows, open build/SculptForge.app on macOS. cpack in the build directory produces platform packages.

Constraints to know

• Early-release maturity. The README labels v0.8 an early release. Multiresolution subdivision levels, dynamic topology and UV editing are listed as not yet available on the roadmap, though the v0.8 notes mention dynamic topology and sculpt layers on every subdivision level, so check the current changelog before relying on these.
• Format limits. Proprietary .ZTL/.ZPR files are not read directly; convert via GoZ, OBJ, FBX, GLB or the ZTool Export plug-in. The GoZ live bridge has not yet been tested against a running ZBrush.
• AI network and licensing. Free AI features depend on third-party online services (Pollinations.ai, Hugging Face demos) and send requests externally; each model has its own licence. Offline use requires Ollama, LM Studio or a self-hosted ComfyUI. The app itself has no telemetry, accounts or its own servers.
• Platforms and signing. Builds cover x86_64 Windows/macOS/Linux plus ARM64 packages, and none are code-signed.