An Aseprite script to ease exporting a bunch of layers and groups into packed sprite sheets (a.k.a. texture atlases).

Export Groups.lua

-- This script will:
-- (1) Flatten each group into a layer;
-- (2) Invoke the 'export sprite sheet' command;
-- (3) Undo the changes.
--
-- v1.0: Initial version.
--
-- Ref: https://github.com/aseprite/aseprite/blob/main/src/app/commands/cmd_export_sprite_sheet.cpp

local spr = app.activeSprite
if not spr then
  return app.alert "You should have an sprite opened"
end

local function exportGroups()
  app.transaction(function()
    for i,layer in ipairs(spr.layers) do
      if layer.isGroup then
        local name = layer.name
        app.range.layers = { layer }
        app.command.FlattenLayers(false)
        spr.layers[i].name = name
      end
    end
  end)
  app.command.ExportSpriteSheet {
    splitLayers=true,
  }
  app.undo()
end

exportGroups()