UVgami now lets you edit unwrap regions by hand

Automatic unwrapping sooner or later runs into a model where the algorithm cuts in the wrong places. In UVgami the artist can now step into that stage. The update of November 7 added the Edit Regions feature: the regions the service automatically splits the model into can be changed by hand. The same update introduced symmetry for individual parts of the model (Per-part symmetry), and the developer reworked the painting of restricted zones for seams and the proxy mode.

UVgami runs right in the browser. You drag the model onto the page, press Unwrap and download a file with a UV map ready for texturing. The service is free, requires no account and does not limit the number of models. Unwrapped models can be used in commercial projects.

“Unwrapping runs locally in your browser, so your models never leave your computer.”
— from the frequently asked questions on the UVgami site

For studios working under NDA, this probably settles the main question about any online tool: the asset does not leave for someone else's server.

From full automation to manual editing

The November update continues a series of changes the developer released over the course of October. Each of them addresses a specific task a modeller brings to automatic unwrapping:

• Hard Surface (October 11) — a mode for models with sharp edges and creases. According to the add-on's description, seams in this mode move to hard edges: there are more islands, but on mechanical and man-made objects the seams hide better.
• Auto (October 12) — the service itself picks Organic or Hard Surface for each part of the model. This may come in handy on models where organic forms are combined with hard elements, for example a character with a weapon or in armour.
• Seam Restrictions (October 14) — a brush paints the areas where there should be no seams: for example a character's face or the front of the model. On November 7 the tool was improved.
• .blend support (October 16) — a scene from Blender can be loaded without an intermediate export.
• Segmentation and Symmetry (October 28) — organic parts of the model are automatically split into separate regions, and the Symmetry option gives symmetrical UVs. The same day the developer improved the Hard Surface and Auto modes.
• Keep Quads (October 29) — an option that, judging by its name, is meant to preserve quad topology.

Edit Regions continues the Segmentation feature. If the automatic split into regions turned out poorly and, say, a hand merged with the forearm, the boundary can now be corrected by hand. Per-part symmetry, in turn, makes it possible to enable mirrored unwrapping only where it is needed: on a symmetrical torso, but not on an asymmetrical accessory.

Formats, speed and the add-on for Blender

The web version accepts OBJ, GLB, GLTF, FBX, STL and .blend files from Blender 4.1 and newer. On output, OBJ and .blend are saved as OBJ, the remaining formats as GLB. That means an uploaded FBX comes back as GLB, and this has to be taken into account when moving the model into your own pipeline.

Unwrapping usually fails on geometry that cannot be flattened: on non-manifold edges and zero-area faces. These will have to be fixed in your own 3D package before uploading. For heavy meshes the developer advises not to turn Proxy off: it is the biggest speed-up for high-poly. The add-on for Blender and the desktop application, where the engine runs natively, work noticeably faster.

Version 2.3.0 of the add-on came out on October 27. According to the documentation it requires Blender 4.3 or newer and works on Windows, Linux and Mac with Intel and Apple Silicon processors. The add-on can unwrap several objects at once, shows the unwrap in real time in a built-in viewer and accepts an existing UV map as a starting point. It stacks similar parts to save texture space, and works with quad topology through the Transfer UVs setting. To the UV editor the add-on adds tools for individual islands and areas: Unwrap Island, Relax Island, Combine Islands, Unwrap Area and Relax Area. The proxy mode, according to the description on the page on Superhive, is intended for meshes of millions of triangles. The add-on can be downloaded free from the UVgami site, and all the money from sales on Superhive goes to the Blender Development Fund.

Where questions remain

The list of changes refers to the site, and from the published materials it is not clear whether Edit Regions and per-part symmetry are present in add-on 2.3.0 and the desktop application: the add-on documentation does not name them. If they are not there, a Blender user may have to return to the browser for manual region editing and account for the change of file format. Another limitation of the web version is speed: on dense meshes the native add-on works faster.

In our estimation, the update is most useful to indie developers, beginning artists and small studios that need an acceptable unwrap without marking seams by hand, without a subscription and without sending assets to the cloud. With manual region editing, the result of automatic unwrapping can be refined rather than accepted wholesale. The developer takes bugs and feature requests in the thread on Blender Artists and in the tracker on GitHub.