Realistic walk/camera script

-- DONT EDIT NOTHING IN THE SCRIPT IF YOU DONT KNOW WHAT YOU DOING!
-- This script is for iiFireGamingOfDoom.
--Not mine(comment made by GForcebit--
--Edited by GForcebit--
--Made by: Shematics
wait(2)
local InputService=game:GetService("UserInputService")
local Camera=game.Workspace.CurrentCamera
local Player=game.Players.LocalPlayer
local Character=Player.Character
local Head=Character.Head
local Torso=Character.Torso
local RootPart=Character.HumanoidRootPart
local RootJoint=RootPart.RootJoint
local Neck=Torso.Neck
Camera.FieldOfView=90
Camera.CameraType="Scriptable"
InputService.MouseBehavior = Enum.MouseBehavior.LockCenter
InputService.MouseIconEnabled = false



local v3=Vector3.new
local cf=CFrame.new
local components=cf().components
local inverse=cf().inverse
local fromAxisAngle=CFrame.fromAxisAngle
local atan,atan2=math.atan,math.atan2
local acos=math.acos

local function toAxisAngleFromVector(v)
	local z=v.z
	return z*z<0.99999 and v3(v.y,-v.x,0).unit*acos(-z) or v3()
end

local function AxisAngleLookOrientation(c,v,t)--CFrame,Vector,Tween
	local c=c-c.p
	local rv=(inverse(c)*v).unit
	local rz=rv.z
	return rz*rz<0.99999 and c*fromAxisAngle(v3(rv.y,-rv.x,0),acos(-rz)*(t or 1)) or c
end

local function AxisAngleLookNew(v,t)--CFrame,Vector,Tween
	local rv=v.unit
	local rz=rv.z
	return rz*rz<0.99999 and fromAxisAngle(v3(rv.y,-rv.x,0),acos(-rz)*(t or 1)) or cf()
end

local function AxisAngleLook(c,v,t)--CFrame,Vector,Tween
	local rv=(inverse(c)*v).unit
	local rz=rv.z
	return rz*rz<0.99999 and c*fromAxisAngle(v3(rv.y,-rv.x,0),acos(-rz)*(t or 1)) or c
end




local Sensitivity=0.005


local CameraDirection=Vector3.new(0,0,1)

local function EulerAnglesYX(l)
	local x,z=l.x,l.z
	return atan(l.y/(x*x+z*z)^0.5),-atan2(x,-z)
end

local function AnglesXY(l)
	local z=l.z
	return atan2(l.y,-z),-atan2(l.x,-z)
end

local function MouseMoved(Input)
	if Input.UserInputType==Enum.UserInputType.MouseMovement then
		local dx,dy=Input.Delta.x*Sensitivity,Input.Delta.y*Sensitivity
		local m2=dx*dx+dy*dy
		if m2>0 then
			CameraDirection=(AxisAngleLookOrientation(RootPart.CFrame,CameraDirection)*fromAxisAngle(v3(-dy,-dx,0),m2^0.5)).lookVector
		end
		local RootOrientation=RootPart.CFrame-RootPart.Position
		local RelativeDirection=RootOrientation:inverse()*CameraDirection
		local AngX,AngY=AnglesXY(RelativeDirection)--RootOrientation:inverse()*
		if AngX<-1.57*11/12 then
			local y,z,c,s=RelativeDirection.y,RelativeDirection.z,math.cos(-1.57*11/12-AngX),-math.sin(-1.57*11/12-AngX)
			z,y=z*c-y*s,z*s+y*c
			CameraDirection=RootOrientation*v3(RelativeDirection.x<0 and -(1-y*y-z*z)^0.5 or (1-y*y-z*z)^0.5,y,z)
		elseif AngX>1.57*11/12 then
			local y,z,c,s=RelativeDirection.y,RelativeDirection.z,math.cos(1.57*11/12-AngX),-math.sin(1.57*11/12-AngX)
			z,y=z*c-y*s,z*s+y*c
			CameraDirection=RootOrientation*v3(RelativeDirection.x<0 and -(1-y*y-z*z)^0.5 or (1-y*y-z*z)^0.5,y,z)
		end
	end
end

local Mouse=Player:GetMouse()

local Zoom=-0.5

Mouse.KeyDown:connect(function(k)
	if k=="e" then
		Zoom=-0.5
	elseif k=="q" then
		Zoom=-0.5
	end
end)

InputService.InputChanged:connect(MouseMoved)

Neck.C1=cf()

local _
local DirectionBound=3.14159/3
local CurrentAngY=0

local function CameraUpdate()
	Camera.CameraType="Scriptable"
	local cx,cz=CameraDirection.x,CameraDirection.z
	local rvx,rvz=RootPart.Velocity.x,RootPart.Velocity.z
	if rvx*rvx+rvz*rvz>4 and cx*rvx+cz*rvz<-0.5*(cx*cx+cz*cz)^0.5*(rvx*rvx+rvz*rvz)^0.5 then
		DirectionBound=math.min(DirectionBound*0.9,math.abs(CurrentAngY*0.9))
	else
		DirectionBound=DirectionBound*0.1+3.14159/3*0.9
	end
	local AngX,AngY=EulerAnglesYX((RootPart.CFrame-RootPart.Position):inverse()*CameraDirection)
	if AngY>DirectionBound then
		RootPart.CFrame=RootPart.CFrame*CFrame.Angles(0,AngY-DirectionBound,0)
	elseif AngY<-DirectionBound then
		RootPart.CFrame=RootPart.CFrame*CFrame.Angles(0,AngY+DirectionBound,0)
	end
	_,CurrentAngY=EulerAnglesYX((RootPart.CFrame-RootPart.Position):inverse()*CameraDirection)
	local CameraOrientation=AxisAngleLookNew((RootPart.CFrame-RootPart.Position):inverse()*CameraDirection,1)
	Neck.C0=CFrame.new(0,1,0)*CameraOrientation*CFrame.new(0,0.5,0)
	local PreCam=AxisAngleLook(RootPart.CFrame*cf(0,1,0),RootPart.CFrame*v3(0,1,0)+CameraDirection)*CFrame.new(0,0.825,0)
	if Zoom==8 then
		local Part,Position=Workspace:findPartOnRay(Ray.new(PreCam.p,PreCam.lookVector*-8),Character)
		Camera.CoordinateFrame=PreCam*CFrame.new(0,0,(Position-PreCam.p).magnitude)
	else
		Camera.CoordinateFrame=PreCam*CFrame.new(0,0,Zoom)
	end
end

game:GetService("RunService").RenderStepped:connect(CameraUpdate)