trackEntry.alpha¶

Type: number

Overview:¶

Values < 1 mix this animation with the skeleton’s current pose (usually the pose resulting from lower tracks). Defaults to 1, which overwrites the skeleton’s current pose with this animation. Typically track 0 is used to completely pose the skeleton, then alpha is used on higher tracks. It doesn’t make sense to use alpha on track 0 if the skeleton pose is from the last frame render.

Example:¶

local lastTime = system.getTimer()

local spine = require("plugin.spine")
local atlas = spine.loadAtlas("assets/characters/hero.atlas")
local skeletonData = spine.loadSkeletonData("assets/characters/hero.skel", atlas)
local hero = spine.create(skeletonData)

-- Set the "idle" animation on track 1 with a 50% mix
hero:setAnimation(1, "idle", true)
hero.tracks[1].alpha = 0.5

-- Transition to the "walk" animation with a 75% mix
hero:addAnimation(1, "walk", true, 1000)

-- Update the animation state each frame
local function onEnterFrame(event)
    local time = system.getTimer()
    local dt = time - lastTime
    lastTime = time

    hero:updateState(dt)
    hero:draw()
end

Runtime:addEventListener("enterFrame", onEnterFrame)