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PlatformerController: is inertia (Mario physics) possible ?
Hello,
I'm using the PlatformerController script from the 2D Gameplay tutorial and was wondering how easy or how hard it was to make the character behave with more realistic controls.
For example, when the character runs in one direction and then he receive commands to go the opposite way, I would want the physic to react accordingly and NOT having the character immediately go in the opposite direction with immediate full speed. I would also want this kind of behavior in mid-air... everything like in Super Mario Bros.
Can someone help ? I'm a real newb... :(
Thank you.
So do u mean like if u were running in full speed you would like slide then turn?
Answer by skovacs1 · Aug 18, 2010 at 08:57 PM
You will need to change the code that calculates movement to take into account momentum yourself. Something like using directed speed should work, but since you want the character to run in the opposite direction of which they are moving when sliding, you will need to store it separately from the momentum. Something like changing the code in PlatformerControllerMovement, UpdateSmoothedMovementDirection and Update like so:
//PlatformerControllerMovement...{... // The current movement momentum. This gets smoothed by speedSmoothing. @System.NonSerialized var momentum = 0.0; //...}
//UpdateSmoothedMovementDirection...{... // Choose target speed var targetSpeed = Mathf.Clamp(h,-1.0,1.0);
// Pick speed modifier
if (Input.GetButton ("Fire2") && canControl)
targetSpeed *= movement.runSpeed;
else
targetSpeed *= movement.walkSpeed;
//Calculate the speed to move at
movement.speed = Mathf.Lerp (movement.speed, Mathf.Abs(targetSpeed), curSmooth);
var traction = GetSurfaceTraction(); //Decide how you want to get this
// Less traction = less change to momentum
curSmooth *= traction;
//Calculate the speed to actually apply as motion
movement.momentum = Mathf.Lerp (movement.momentum, targetSpeed, curSmooth);
//...}
//Update...{... // Calculate actual motion var currentMovementOffset = Vector3(movement.momentum, movement.verticalSpeed, 0) + movement.inAirVelocity; //...}
This way, the momentum representing the speed at which the character will be translated will slow down according to smoothing and friction, while the movement speed of the character as it animates will behave as before (since it has less effect than before, you may consider even removing the smoothing from speed altogether and only applying it to the momentum).
EDIT 08/30: I'm not sure what problems you could be having in making these three simple changes, but here is the complete working script with the changes:
// Does this script currently respond to Input? var canControl = true;
// The character will spawn at spawnPoint's position when needed. This could be changed via a script at runtime to implement, e.g. waypoints/savepoints. var spawnPoint : Transform;
class PlatformerControllerMovement { // The speed when walking var walkSpeed = 3.0; // when pressing "Fire1" button (control) we start running var runSpeed = 10.0;
var inAirControlAcceleration = 1.0;
// The gravity for the character
var gravity = 60.0;
var maxFallSpeed = 20.0;
// How fast does the character change speeds? Higher is faster.
var speedSmoothing = 2.0;
// This controls how fast the graphics of the character "turn around" when the player turns around using the controls.
var rotationSmoothing = 10.0;
// The current move direction in x-y. This will always been (1,0,0) or (-1,0,0)
// The next line, @System.NonSerialized , tells Unity to not serialize the variable or show it in the inspector view. Very handy for organization!
@System.NonSerialized
var direction = Vector3.zero;
// The current vertical speed
@System.NonSerialized
var verticalSpeed = 0.0;
// The current movement speed. This gets smoothed by speedSmoothing.
@System.NonSerialized
var speed = 0.0;
// The current movement momentum. This gets smoothed by speedSmoothing.
@System.NonSerialized
var momentum = 0.0;
// Is the user pressing the left or right movement keys?
@System.NonSerialized
var isMoving = false;
// The last collision flags returned from controller.Move
@System.NonSerialized
var collisionFlags : CollisionFlags;
// We will keep track of an approximation of the character's current velocity, so that we return it from GetVelocity () for our camera to use for prediction.
@System.NonSerialized
var velocity : Vector3;
// This keeps track of our current velocity while we're not grounded?
@System.NonSerialized
var inAirVelocity = Vector3.zero;
// This will keep track of how long we have we been in the air (not grounded)
@System.NonSerialized
var hangTime = 0.0;
}
var movement : PlatformerControllerMovement;
// We will contain all the jumping related variables in one helper class for clarity. class PlatformerControllerJumping { // Can the character jump? var enabled = true;
// How high do we jump when pressing jump and letting go immediately
var height = 1.0;
// We add extraHeight units (meters) on top when holding the button down longer while jumping
var extraHeight = 4.1;
// This prevents inordinarily too quick jumping
// The next line, @System.NonSerialized , tells Unity to not serialize the variable or show it in the inspector view. Very handy for organization!
@System.NonSerialized
var repeatTime = 0.05;
@System.NonSerialized
var timeout = 0.15;
// Are we jumping? (Initiated with jump button and not grounded yet)
@System.NonSerialized
var jumping = false;
@System.NonSerialized
var reachedApex = false;
// Last time the jump button was clicked down
@System.NonSerialized
var lastButtonTime = -10.0;
// Last time we performed a jump
@System.NonSerialized
var lastTime = -1.0;
// the height we jumped from (Used to determine for how long to apply extra jump power after jumping.)
@System.NonSerialized
var lastStartHeight = 0.0;
}
var jump : PlatformerControllerJumping;
private var controller : CharacterController;
// Moving platform support. private var activePlatform : Transform; private var activeLocalPlatformPoint : Vector3; private var activeGlobalPlatformPoint : Vector3; private var lastPlatformVelocity : Vector3;
// This is used to keep track of special effects in UpdateEffects (); private var areEmittersOn = false;
function Awake () { movement.direction = transform.TransformDirection (Vector3.forward); controller = GetComponent (CharacterController); Spawn (); }
function Spawn () { // reset the character's speed movement.verticalSpeed = 0.0; movement.speed = 0.0;
// reset the character's position to the spawnPoint
transform.position = spawnPoint.position;
}
function OnDeath () { Spawn (); }
function UpdateSmoothedMovementDirection () {
var h = Input.GetAxisRaw ("Horizontal");
if (!canControl)
h = 0.0;
movement.isMoving = Mathf.Abs (h) > 0.1;
if (movement.isMoving)
movement.direction = Vector3 (h, 0, 0);
// Grounded controls
if (controller.isGrounded) {
// Smooth the speed based on the current target direction
var curSmooth = movement.speedSmoothing * Time.deltaTime;
// Choose target speed
var targetSpeed = Mathf.Clamp(h,-1.0,1.0);
// Pick speed modifier
if (Input.GetButton ("Fire2") && canControl)
targetSpeed *= movement.runSpeed;
else
targetSpeed *= movement.walkSpeed;
//Calculate the speed to move at
movement.speed = Mathf.Lerp (movement.speed, Mathf.Abs(targetSpeed), curSmooth);
var traction = 0.5; //Decide how you want to get this
// Less traction = less change to momentum
curSmooth *= traction;
//Calculate the speed to actually apply as motion
movement.momentum = Mathf.Lerp (movement.momentum, targetSpeed, curSmooth);
movement.hangTime = 0.0;
}
else {
// In air controls
movement.hangTime += Time.deltaTime;
if (movement.isMoving)
movement.inAirVelocity += Vector3 (Mathf.Sign(h), 0, 0) * Time.deltaTime * movement.inAirControlAcceleration;
}
}
function FixedUpdate () { // Make sure we are absolutely always in the 2D plane. transform.position.z = 0;
}
function ApplyJumping () { // Prevent jumping too fast after each other if (jump.lastTime + jump.repeatTime > Time.time) return;
if (controller.isGrounded) {
// Jump
// - Only when pressing the button down
// - With a timeout so you can press the button slightly before landing
if (jump.enabled && Time.time < jump.lastButtonTime + jump.timeout) {
movement.verticalSpeed = CalculateJumpVerticalSpeed (jump.height);
movement.inAirVelocity = lastPlatformVelocity;
SendMessage ("DidJump", SendMessageOptions.DontRequireReceiver);
}
}
}
function ApplyGravity () { // Apply gravity var jumpButton = Input.GetButton ("Jump");
if (!canControl)
jumpButton = false;
// When we reach the apex of the jump we send out a message
if (jump.jumping && !jump.reachedApex && movement.verticalSpeed <= 0.0) {
jump.reachedApex = true;
SendMessage ("DidJumpReachApex", SendMessageOptions.DontRequireReceiver);
}
// * When jumping up we don't apply gravity for some time when the user is holding the jump button
// This gives more control over jump height by pressing the button longer
var extraPowerJump = jump.jumping && movement.verticalSpeed > 0.0 && jumpButton && transform.position.y < jump.lastStartHeight + jump.extraHeight && !IsTouchingCeiling ();
if (extraPowerJump)
return;
else if (controller.isGrounded)
movement.verticalSpeed = -movement.gravity * Time.deltaTime;
else
movement.verticalSpeed -= movement.gravity * Time.deltaTime;
// Make sure we don't fall any faster than maxFallSpeed. This gives our character a terminal velocity.
movement.verticalSpeed = Mathf.Max (movement.verticalSpeed, -movement.maxFallSpeed);
}
function CalculateJumpVerticalSpeed (targetJumpHeight : float) { // From the jump height and gravity we deduce the upwards speed // for the character to reach at the apex. return Mathf.Sqrt (2 targetJumpHeight movement.gravity); }
function DidJump () { jump.jumping = true; jump.reachedApex = false; jump.lastTime = Time.time; jump.lastStartHeight = transform.position.y; jump.lastButtonTime = -10; }
function UpdateEffects () { wereEmittersOn = areEmittersOn; areEmittersOn = jump.jumping && movement.verticalSpeed > 0.0;
// By comparing the previous value of areEmittersOn to the new one, we will only update the particle emitters when needed
if (wereEmittersOn != areEmittersOn) {
for (var emitter in GetComponentsInChildren (ParticleEmitter)) {
emitter.emit = areEmittersOn;
}
}
}
function Update () { if (Input.GetButtonDown ("Jump") && canControl) { jump.lastButtonTime = Time.time; }
UpdateSmoothedMovementDirection();
// Apply gravity
// - extra power jump modifies gravity
ApplyGravity ();
// Apply jumping logic
ApplyJumping ();
// Moving platform support
if (activePlatform != null) {
var newGlobalPlatformPoint = activePlatform.TransformPoint(activeLocalPlatformPoint);
var moveDistance = (newGlobalPlatformPoint - activeGlobalPlatformPoint);
transform.position = transform.position + moveDistance;
lastPlatformVelocity = (newGlobalPlatformPoint - activeGlobalPlatformPoint) / Time.deltaTime;
} else {
lastPlatformVelocity = Vector3.zero;
}
activePlatform = null;
// Save lastPosition for velocity calculation.
lastPosition = transform.position;
// Calculate actual motion
var currentMovementOffset = Vector3(movement.momentum, movement.verticalSpeed, 0) + movement.inAirVelocity;
// We always want the movement to be framerate independent. Multiplying by Time.deltaTime does this.
currentMovementOffset *= Time.deltaTime;
// Move our character!
movement.collisionFlags = controller.Move (currentMovementOffset);
// Calculate the velocity based on the current and previous position.
// This means our velocity will only be the amount the character actually moved as a result of collisions.
movement.velocity = (transform.position - lastPosition) / Time.deltaTime;
// Moving platforms support
if (activePlatform != null) {
activeGlobalPlatformPoint = transform.position;
activeLocalPlatformPoint = activePlatform.InverseTransformPoint (transform.position);
}
// Set rotation to the move direction
if (movement.direction.sqrMagnitude > 0.01)
transform.rotation = Quaternion.Slerp (transform.rotation, Quaternion.LookRotation (movement.direction), Time.deltaTime * movement.rotationSmoothing);
// We are in jump mode but just became grounded
if (controller.isGrounded) {
movement.inAirVelocity = Vector3.zero;
if (jump.jumping) {
jump.jumping = false;
SendMessage ("DidLand", SendMessageOptions.DontRequireReceiver);
var jumpMoveDirection = movement.direction * movement.speed + movement.inAirVelocity;
if (jumpMoveDirection.sqrMagnitude > 0.01)
movement.direction = jumpMoveDirection.normalized;
}
}
// Update special effects like rocket pack particle effects
UpdateEffects ();
}
function OnControllerColliderHit (hit : ControllerColliderHit) { if (hit.moveDirection.y > 0.01) return;
// Make sure we are really standing on a straight platform
// Not on the underside of one and not falling down from it either!
if (hit.moveDirection.y < -0.9 && hit.normal.y > 0.9) {
activePlatform = hit.collider.transform;
}
}
// Various helper functions below: function GetSpeed () { return movement.speed; }
function GetVelocity () { return movement.velocity; }
function IsMoving () { return movement.isMoving; }
function IsJumping () { return jump.jumping; }
function IsTouchingCeiling () { return (movement.collisionFlags & CollisionFlags.CollidedAbove) != 0; }
function GetDirection () { return movement.direction; }
function GetHangTime() { return movement.hangTime; }
function Reset () { gameObject.tag = "Player"; }
function SetControllable (controllable : boolean) { canControl = controllable; }
// Require a character controller to be attached to the same game object @script RequireComponent (CharacterController) @script AddComponentMenu ("2D Platformer/Platformer Controller")
What I want to know precisely is how to change the PlatformerController behavior so that when I press a key to turn around when already at high velocity, the character cannot immediately go to the opposite direction since he has too much speed. What I want is the character to turn around immediately (which is already working) and start running in the opposite direction while still being dragged a bit to the previous way he was going.
The way it is right now, the character keeps it's full velocity when he turns around (as if, let's say velocity 15 became -15 right away, which is not right).
Hmmm... for whatever reason, when I modify the script with your stuff, the whole script gets ignored and I get errors about 2 Audio Listeners, saying there should be only one. Even if I deleted everything inside the script and saved it, I can still play as if the script was always there.
Which of those should I use to edit a script ? - Double Click on the script inside the Properties Editor - Click once on the script inside the Project window to make the script appear in the Inspector, then click the "Edit" button - Double Click the script inside the the Project window
Sorry to be a newb. :(
That's strange. The above changes clearly have nothing to do with audio listeners. I recall occasions where script/shader errors and warnings broke my application and Unity 2.6 would just use previously successfully compiled version. It doesn't matter how you edit your script as long as you save your changes (you could open it externally without Unity open even), Unity should pick up the changes and re-compile. Best practice is to make sure to always check the log for errors and warnings and fix them all and for good measure restart Unity. $$anonymous$$y changes were simple and shouldn't break anything.
I noticed that the Windows version seems a bit buggier than it's $$anonymous$$ac counterpart. I might try this out on my $$anonymous$$ac tonight and see what happens.
Or maybe I didn't insert your code at the right places... ? $$anonymous$$y program$$anonymous$$g knowledge is pretty poor so I might do something wrong. I'll try on my $$anonymous$$ac first and see if I'm going somewhere with this...
Thanks for trying to help me, by the way! :)
I don't know what to say Phil. I've pulled up the 2D Gameplay Tutorial, added the exact changes above and got the results that you were asking about, playing with the traction to get the feel of different surfaces. To get more realistic results than that, tune the speedSmoothing and walk/run speeds to something more natural.
Answer by Ehren · Aug 18, 2010 at 06:09 PM
Have you tried tweaking the PlatformerController's acceleration properties?
EDIT: These are the properties I was referring to (I should have said "smoothing" rather than acceleration). Try lowering them.
// How fast does the character change speeds? Higher is faster. var speedSmoothing = 5.0;
// This controls how fast the graphics of the character "turn around" when the player turns around using the controls. var rotationSmoothing = 10.0;
Tweaking that property (inAirControlAcceleration) doesn't do anything close to what I'm searching for. I'm not sure which parameters I have to fiddle with in order to achieve this.
I have the feeling that I have to insert a new formula or change an existing one in order to do it. Tweaking a variable won't work, I think.
Answer by formidable · Aug 17, 2011 at 02:27 PM
I'm just starting to learn unity so I have little or no idea what I'm doing but I remember these guys talking about smooth rotation of the head when using your mouse to aim where it's looking at, instead of instantly looking in that direction.
http://unity3d.com/support/old-resources/unite-presentations/character-animation-tips-amp-tricks
Answer by JohnnyA · Mar 12, 2013 at 09:29 AM
Check out my 2D controller from the Asset Store: http://forum.unity3d.com/threads/173640-Released-2D-Platform-Controller
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