Lerping a full rotation (360)

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1

I am trying to lerp an item to perform a full 360 rotation about the y-axis about its origin once. However, if I make it lerp 360 in a single motion, it ends up not moving at all. I assume that it is the system thinking I didn’t move since my final position is the same as my start. Is there a possible way to make it do a smooth and continuous 360 movement? Maybe lerping multiple times or any other way? And no, I don’t want to tween or anything, it has to be lerp.

1 Like
2

I would use tweens, but if you insist,

local Part = workspace.Part

for i = 1,360 do
	Part.CFrame = Part.CFrame * CFrame.Angles(0,math.rad(1),0)
	task.wait()
end

or

local Part = workspace.Part

function Lerp(a, b, t)
	return a + (b - a) * t
end

local degreesOfRotation = 360

for i = 1,degreesOfRotation do
	Part.Orientation = Vector3.new(0,Lerp(0, 360, i/360),0)
	task.wait()
	end
3

I have trouble the same problem, I have created this lerp function to lerp angles (-180 - 180):

function LerpAngle(A: number, B: number, Time: number): number
    local AngleResult: {
        MaxAngle: number,
        Cost: number,
        StartTime: number,
        EndTime: number
    }?

    -- Check if can do angle lerp
    for I = 1,2 do
        -- Check if cost is lower than normal method
        local MaxAngle = I == 1 and 180 or -180
        local AngleA = MaxAngle > 0 and math.abs(A) or -math.abs(A)
        local Cost: number
        if MaxAngle == -180 then
            -- 180 --> -180
            Cost = math.abs(180 - A) + math.abs(-180 + math.abs(B))
        else
            -- -180 --> 180
            Cost = math.abs(180 + A) + math.abs(180 - math.abs(B))
        end

        local COST_IS_HIGHER = not AngleResult and Cost > math.abs(B - A) or AngleResult and Cost > AngleResult.Cost
        if COST_IS_HIGHER then
            continue
        end

        -- Calcule lerp time
        local StartTime = math.abs(MaxAngle - AngleA) / Cost
        local EndTime = (180 - math.abs(B)) / Cost

        if StartTime < 0 then
            EndTime -= StartTime
            StartTime = math.abs(StartTime)
        end
        if EndTime < 0 then
            StartTime -= EndTime
            EndTime = math.abs(EndTime)
        end

        AngleResult = {
            MaxAngle = MaxAngle,
            Cost = Cost,
            StartTime = StartTime,
            EndTime = EndTime
        }
    end

    if not AngleResult then
        -- If not triggered angle lerp, then calcule default lerp
        return A + (B - A) * Time
    end

    -- Calcule angle lerp
    local MaxAngle = AngleResult.MaxAngle

    if Time <= AngleResult.StartTime then
        local TimeA = Time / AngleResult.StartTime
        local Increase = (180 - math.abs(A)) * TimeA

        if MaxAngle == -180 then
            return A + Increase
        else
            return A - Increase
        end

        return
    end

    local TimeB = 1 - ((Time - AngleResult.StartTime) / AngleResult.EndTime)
    local Decrease = (180 - math.abs(B)) * TimeB

    if MaxAngle == -180 then
        return B - Decrease
    else
        return B + Decrease
    end
end

Work like a normal lerp function:

local CurrentAngleY = LerpAngle(StartY, GoalY, Time)

I hope can help :pray: