Launched in the late 2000s, TopoGun became one of the first tools for retopologizing high-resolution models, enabling artists to convert sculptures into lower-polygon and animation-friendly objects.

Despite being widely used, TopoGun seemed to have entered a period of relative inactivity after the release of TopoGun 2 in 2012. Public activity was scarce until the beta version of TopoGun 3 was released in 2020.
The workflow in TopoGun typically starts with importing a high-resolution reference mesh for retopology, such as a sculpture or 3D scan, which can be imported as FBX or OBJ in TopoGun 3. Users can plan new topology, drawing strokes on the source mesh with the Guide Lines tool to create common edges. Then, the new geometry can be drawn directly on the surface of the source mesh and adjusted using various editing tools, working on multiple vertices at once or employing the pressure-sensitive Brush tool for moving or relaxing large vertex selections.
Users can restrict editing to specific areas of the mesh using the Mask tool for painting masks. In TopoGun 3, new tools like Slice and Cut have been introduced for cutting mesh geometry, and Circle and Shell, the latter of which is used for creating clothing from the mesh surface. The Tubes tool, used for retopologizing cylindrical parts of the mesh like limbs, has been rewritten.
While TopoGun primarily emphasizes manual retopology, it also supports automatic retopology for parts of the mesh where precise vertex placement is less critical, such as ears.

TopoGun 3 introduces a fresh approach to combining manual and automatic work through the Patch tool, which is one of the most intriguing features of this release. With the Patch tool, users can sketch new topology for key areas of a sculpture, following anatomical landmarks, as demonstrated in the image above, and automatically generate new topology within them using TopoGun. These parts can then be connected to create a continuous, new low-polygon surface for the entire model.
Another key feature of TopoGun is Subdivision, which subdivides the retopologized low-resolution mesh to preserve the fine details of the source mesh. Details can also be transferred to the mesh after retopology using texture maps generated based on the high-resolution source mesh: TopoGun 3 can create normal, displacement, occlusion, color, curvature, transmission, and cavity maps. Both the subdivision and baking processes are highly multi-threaded, with TopoGun 3 supporting up to 256 CPU cores, and occlusion map baking is now accelerated on the GPU using OpenGL.

TopoGun 3 is compatible with Windows 7 and later, as well as macOS 10.13 and later. The node-locked license costs $149.99, while the floating node license is priced at $349.99. If you're upgrading from TopoGun 2, the cost is $29.99 for the node-locked license and $74.99 for the floating node license.