skin:getConstraints()¶

Type: function

Overview¶

Returns the constraints associated with this skin. Some skins in Spine can include constraint data (IK, transform, path, etc.) for skin-specific behavior.

Syntax¶

local constraints = skin:getConstraints()

Return value¶

table – Array of constraint names (strings) associated with this skin.

Example¶

The examples use the mix-and-match example skeleton, whose skins each dress part of the character.

List Skin Constraints¶

local girl = spine.create(spine.loadSkeletonData("assets/characters/mix-and-match.json",
                                                 spine.loadAtlas("assets/characters/mix-and-match.atlas")))

girl:setSkin("full-skins/girl")
local skin = girl:getSkin()
local constraints = skin:getConstraints()

if #constraints > 0 then
    print("Skin-specific constraints:")
    for i, constraintName in ipairs(constraints) do
        print("  -", constraintName)
    end
else
    print("No skin-specific constraints")
end

Check Constraint Requirements¶

local girl = spine.create(spine.loadSkeletonData("assets/characters/mix-and-match.json",
                                                 spine.loadAtlas("assets/characters/mix-and-match.atlas")))

local function validateSkinCompatibility(skinName)
    local skin = girl:findSkin(skinName)

    if skin then
        local constraints = skin:getConstraints()

        if #constraints > 0 then
            print("Warning: Skin requires special constraints:")
            for _, name in ipairs(constraints) do
                print("  -", name)
            end
            return false
        end
    end

    return true
end

validateSkinCompatibility("accessories/hat-red-yellow")

Preserve Constraints When Combining¶

local girl = spine.create(spine.loadSkeletonData("assets/characters/mix-and-match.json",
                                                 spine.loadAtlas("assets/characters/mix-and-match.atlas")))

local customSkin = girl:createSkin("advanced")

-- Add skins with constraints
customSkin:addSkin("skin-base")
customSkin:addSkin("accessories/hat-red-yellow")  -- Has a skin constraint

local constraints = customSkin:getConstraints()
print("Combined skin has", #constraints, "constraints")

-- All constraints are preserved when combining skins
girl:setSkin(customSkin)

Notes¶

Returns an empty table if the skin has no associated constraints
Skin constraints are an advanced Spine feature used with skin-specific IK, transforms, etc.
When using skin:addSkin() or skin:copySkin(), constraint data is preserved
Most simple skins will return an empty table
Constraints can include: IK, transform, path, and physics constraints