muhuk / grid-uv-packer

Grid UV Packer

Deprecation Warning: Blender 3.6.0 has this functionality built-in. You are advised to uninstall this addon.

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A pure-Python UV packer that packs irregularly shaped UV islands efficiently.

grid-uv-packer is released with GPL license, same as Blender

Features

• Packs UV islands trying to utilize all available space.
• Uses multi-processing to run multiple iterations in parallel.

Installation

• Download the source zip from releases page. You need to click to expand Assets under the correct version and download the file named guvp-#.#.zip (where #.# is the version number)
• In Blender, open Preferences editor (Edit -> Preferences from the menu).
• Click Install... button and choose the zip file you have downloaded.
• Once the addon is installed, you must still enable it manually in Preferences view. It is not automatically enabled.
• After installation, you can delete the zip file you have downloaded.

Usage

Once you enable the addon, in UV editor a Grid UV Pack command will be available under UV menu. This command will create a modal dialog where you can adjust operator parameters. Operator will start to run once you click OK on this modal dialog.

Note that operator only packs selected islands, same behavior as Pack Islands.

Parameters

Pack to : This is same as Pack Islands operator. Closest UDIM packs into the tile closest to the selection's center, Active UDIM packs into the active tile (if a tiled image is loaded) or the tile closest to 2D cursor.

Grid Size : Resolution of the grid used by the algorithm. Increasing this parameter can result in more tightly packed UV maps at the cost of time. This parameter should be adjusted with 2 things in mind; the number of islands and image dimensions. As a rough estimate 64 and 128 is good for 1K images, 512 should only be used for 8K textures for very dense meshes.

Rotate : Whether to rotate islands or not during packing. This is same as Pack Islands.

Margin : Spacing (in terms of UV space) in between islands. Althogh Pack Islands also have a parameter with the same name, it works differently in this operator. Margin is taken into account, but the result might have more spacing.

Max Iterations : Maximum number of iterations. When the calculation ends, result with the best coverage will be used. Due to brute force nature of this operator, setting this to a low number will yield poor results, expecially with UV maps with many islands. Note that calculation may be stopped before this number of iterations are run.

Max Runtime : Maximum amount of time the calculation is allowed to run. Set this to 0 to disable time limit.

Random Seed : Seed used to initialize the random number generator. If this is set to 0 a random number will be generated every time you run the operator. You don't need to modify this normally.