Procedural walk animation footplanting

local player = game:GetService("Players").LocalPlayer
local character = player.Character
local rootPart = character.HumanoidRootPart
local head = character.Head --lower torso when actual character
local camera = workspace.CurrentCamera

local beam1, beam2 = workspace.beam1, workspace.beam2
local pos1, pos2 = workspace.pos1, workspace.pos2

local cf = CFrame.new
local ang = CFrame.Angles
local v3 = Vector3.new
local ray = Ray.new
local sin = math.sin
local pi = math.pi
local rad = math.rad
local deg = math.deg

local lastUpdate = 0
local targLeft, targRight = v3(), v3()
local oldLeft, oldRight = v3(), v3()
local updateLeft = true
local leftOff, rightOff = cf(-0.5, -0.5, 0), cf( 0.5, -0.5, 0)
local lastspeed = 0

local function getVel()
    local vel = rootPart.CFrame:vectorToObjectSpace(rootPart.Velocity)
    local speed = v3(vel.X, 0, vel.Z).magnitude
    return vel, speed
end

local function getDirection()
    local direction = camera.CFrame.lookVector
    local heading = math.atan2(-direction.X, -direction.Z)
    return heading
end

local function predictPosition(current, velocity, timeAhead)
    return current * cf(velocity * timeAhead)
end

local function getNextPosition(origin, zAngle, xAngle, length)
    local start = origin * ang(zAngle, 0, 0) * ang(0, 0, xAngle)
    local ray = ray(start.p, -start.UpVector * length)
    local hit, pos, nor = workspace:FindPartOnRayWithIgnoreList(ray, {character, beam1, beam2, pos1, pos2, workspace.Ignore})
    return pos
end

local function getLegToUpdate(predictedcf, vel)
    local nextLeft = getNextPosition(predictedcf * leftOff, rad(-vel.Z), rad(vel.X), 3)
    local nextRight = getNextPosition(predictedcf * rightOff, rad(-vel.Z), rad(vel.X), 3)
    local relLeft = (predictedcf:PointToObjectSpace((nextLeft + targRight)/2) * v3(1, 0, 1)).magnitude
    local relRight = (predictedcf:PointToObjectSpace((nextRight + targLeft)/2) * v3(1, 0, 1)).magnitude
    if relRight > relLeft then
        return true, nextLeft
    else
        return false, nextRight
    end
end

local function updateLegs(leftOrigin, rightOrigin, leftPos, rightPos)
    local d1 = (leftOrigin.p - leftPos).magnitude
    beam1.Size = v3(0.5, 0.5, d1)
    beam1.CFrame = cf(leftOrigin.p, leftPos) * cf(0, 0, -d1/2)
    local d2 = (rightOrigin.p - rightPos).magnitude
    beam2.Size = v3(0.5, 0.5, d2)
    beam2.CFrame = cf(rightOrigin.p, rightPos) * cf(0, 0, -d2/2)
end

game:GetService("RunService").RenderStepped:Connect(function(s)
    local vel, speed = getVel()
    local direction = getDirection()
    rootPart.CFrame = cf(rootPart.Position) * ang(0, direction, 0)
    local leftSet, rightSet
    if speed > 0 or math.abs(lastspeed-speed)/s > 0  then
        local delayOf = 0.3
        if lastUpdate + delayOf < tick() then
            lastUpdate = tick()
            local predictedcf = predictPosition(head.CFrame, vel, delayOf)--*1.5)
            local leftLeg, setPos = getLegToUpdate(predictedcf, vel)
            updateLeft = leftLeg
            if leftLeg then
                oldLeft = targLeft
                targLeft = setPos
            else
                oldRight = targRight
                targRight = setPos
            end
        end
        local alpha = math.min((tick()-lastUpdate)/(delayOf/2), 1)
        if updateLeft then
            leftSet = oldLeft:lerp(targLeft, alpha) + v3(0, 0.75*sin(pi*alpha), 0)
            rightSet = targRight
        else
            rightSet = oldRight:lerp(targRight, alpha) + v3(0, 0.75*sin(pi*alpha), 0)
            leftSet = targLeft
        end
        else
        targLeft = getNextPosition(head.CFrame * leftOff, rad(10), rad(-5), 3)
        targRight = getNextPosition(head.CFrame * rightOff, rad(-10), rad(5), 3)
        oldLeft, oldRight = targLeft, targRight
        leftSet, rightSet = targLeft, targRight
    end
    pos1.Position = leftSet
    pos2.Position = rightSet
    updateLegs(head.CFrame * leftOff, head.CFrame * rightOff, leftSet, rightSet)
    lastspeed = speed
end)