FrontSurfaceInput

Property of: BasePart

Description:

The FrontSurfaceInput property determines the kind of input provided to a part’s /BasePart/FrontSurface. This is only relevant for Motor or SteppingMotor SurfaceTypes. This property determines how /BasePart/FrontParamA and /BasePart/FrontParamB are used. For brevity, these properties will be referred to as ParamA and ParamB, respectively.

By default, this is set to NoInput. This stops the motor altogether,
For Constant, the motor rotates at a constant velocity equal to ParamB.
For Sin, the motor rotates at a velocity equal to ParamA * math.sin(workspace.DistributedGameTime * ParamB). See /Workspace/DistributedGameTime.

Code Samples

Motor Control

This code sample demonstrates how surface properties can be set using only a NormalId (Top, Front, etc). It switches a motor’s -SurfaceInput from NoInput, Constant and Sin to show how each work using -ParamA and -ParamB properties.

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-- Paste this into a Script inside a part with a Motor SurfaceType
local partMotor = script.Parent
-- Place a brick called "MovingPart" so it is touching the Motor surface
local partMoving = partMotor.Parent.MovingPart

-- For this example, we use TopSurface, TopSurfaceInput, TopParamA and TopParamB
-- However, this will work for all faces (NormalId): Top, Bottom, Left, Right, Front and Back

-- A function to quickly set all surface properties at once 
local function setFaceSurfaceInputParams(normalId, surfaceType, inputType, paramA, paramB)
	local surfaceName = normalId.Name -- e.g. "Top", "Bottom", etc

	-- Syntax Note: in Lua, part.Something is the same as part["Something"]
	-- The difference is that the latter allows us to use a string ("Something"), while
	-- the former requires use of an identifier (.Something). Below, we build of each the surface
	-- properties below by concatenating the surface name with the property postfix.
	
	-- Set "___Surface", eg "TopSurface"
	partMotor[surfaceName .. "Surface"] = surfaceType
	-- Set "___SurfaceInput", eg "TopSurfaceInput"
	partMotor[surfaceName .. "SurfaceInput"] = inputType
	-- Set "___ParamA", eg "TopParamA"
	partMotor[surfaceName .. "ParamA"] = paramA
	-- Set "___ParamB", eg "TopParamB"
	partMotor[surfaceName .. "ParamB"] = paramB
end

local normalId = Enum.NormalId.Top

while true do
	-- Set to NoInput, where the motor will not operate at all
	setFaceSurfaceInputParams(normalId, Enum.SurfaceType.Motor, Enum.InputType.NoInput, 0, 0)
	wait(1)
	-- Set to Constant, where motor rotational velocity = paramB
	setFaceSurfaceInputParams(normalId, Enum.SurfaceType.Motor, Enum.InputType.Constant, 0, .25)
	wait(2)
	-- Set to Sin, where motor rotational velocity = paramA * math.sin(time * paramB)
	-- Since we're using pi (~3.14), the frequency of rotation is 1 second (per definition of sine function)
	setFaceSurfaceInputParams(normalId, Enum.SurfaceType.Motor, Enum.InputType.Sin, .25, math.pi)
	wait(3)
end

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