Easy Envelope - A Controllable Tool To Weighting/Skinning

Easy Envelope works from pose mode. Select the mesh object first, then the armature object, and enter pose mode, where a start button appears on the N panel to open the addon's interface. After adjusting your settings, press the C key to calculate the weights, and the result is applied to the vertices once calculation finishes. You can preview the outcome in real time as you work, with red showing a weight of 1, blue showing 0, and white marking vertices that have not been processed.

Easy Envelope is aimed at meshes that are not linked to human bones, such as hems of clothes, cloaks, multi-layered skirts, and hair composed of meshes. For complex biological binding like a full human character, where binding involves multiple bones and manually specifying each bone's influence range becomes cumbersome, Blender's heat diffusion algorithm is the more suitable solution. The addon builds on Blender's envelope weight method, which suits meshes with complex structures where automatic heat-diffusion weighting can give uncontrollable or unsatisfactory results.

Easy Envelope's interface is available in English, Chinese, and Japanese, so you can work in whichever of the three you prefer. The addon expands Blender's built-in envelope weight binding, which is otherwise fairly simple and cumbersome to operate and view, adding the ability to customise the envelope range and view it conveniently in real time. You can also see every envelope shape and the vertices each one affects while you work.

Easy Envelope is listed as free in this catalog. For current licensing details, check the developer's page on superhive. Beyond that, the addon replaces Blender's automatic weight algorithms with envelope weight binding you can control directly: each bone has a cylinder-shaped envelope range, vertices inside it are affected by the bone, and the intersecting parts of envelopes form the weight transition. You can edit envelope shapes and save or load them as files.

Easy Envelope can mix its results with existing weights without breaking them, which is useful when weighting something like hair that already has weight. This works only when the processed bones and the bones that already carry weights belong to the same armature. Because the addon assigns weight based on distance, close vertices receive similar weights, which helps keep separated meshes consistent. For separated meshes, assign as solid or gradient a weight as possible, otherwise animation can tear the mesh apart.