Got a few issues with 2D animations

PhantomFox128

Apologies for the huge post.

I'm making a 2D action platformer that uses hand-drawn visuals with a ton of animations that have a lot of frames on them, including some simple one-shot animations that are made purely to transition from one animation to another. The thing is, I'm running into a handful of issues when it comes to animation transitions or just trying to get an animation to play in general.

The animations are put together using AnimationPlayer and I'm also using the AnimationTree state machine to handle transitions more easily, but I'm still running into some problems. Here's my entire code as it currently stands:

extends KinematicBody2D

#VARIABLES
export var walkSpeed: int = 1200;
export var runSpeed: int = 2000;
export var jumpForce: int = 2750;
export var gravity: int = 4500;
export var maxFallSpeed: int = 2750;

export var health: int = 20;

#CHECKS
var isCrouching: bool = false;
var isAttacking: bool = false;

var stateMachine;
var velocity: = Vector2();

func _ready():
	stateMachine = $AnimationTree.get("parameters/playback");

func _process(_delta):
	pass;

func input():
	var current = stateMachine.get_current_node();
	
#MOVEMENT
	if Input.is_action_pressed("right") and !isCrouching and !isAttacking:
		$Sprite.scale.x = 1;
		if Input.is_action_pressed("run"):
			velocity.x = runSpeed;
			if is_on_floor():
				stateMachine.travel("Run");
		else:
			velocity.x = walkSpeed;
			if is_on_floor():
				stateMachine.travel("Walk");
	elif Input.is_action_pressed("left") and !isCrouching and !isAttacking:
		$Sprite.scale.x = -1;
		if Input.is_action_pressed("run"):
			velocity.x = -runSpeed;
			if is_on_floor():
				stateMachine.travel("Run");
		else:
			velocity.x = -walkSpeed;
			if is_on_floor():
				stateMachine.travel("Walk");
	else:
		velocity.x = 0;
		# only play if not crouching
		if !isCrouching and is_on_floor():
			stateMachine.travel("Idle");

#JUMP
	if is_on_floor() and Input.is_action_just_pressed("jump") and !isAttacking:
		velocity.y = -jumpForce;
		stateMachine.travel("Jump");
		
#FALL
	if velocity.y >= 0 and !is_on_floor() and !isAttacking:
		stateMachine.travel("Fall");

#CROUCH
	if is_on_floor() and Input.is_action_pressed("crouch") and velocity.y == 0:
		isCrouching = true;
		$CrouchCollision.disabled = false;
		$BodyCollision.disabled = true;
		stateMachine.travel("Crouch");
	else:
		isCrouching = false;
		$CrouchCollision.disabled = true;
		$BodyCollision.disabled = false;

func _physics_process(delta):
	input();
	velocity.y += gravity * delta;
	if velocity.y > maxFallSpeed:
		velocity.y = maxFallSpeed;
	velocity = move_and_slide(velocity, Vector2.UP);

Here's what the state machine currently looks like:

Now for some of the problems/questions I currently have:

Idle animation doesn't play: For some reason, even though the AnimationTree is set to active and the main idle animation loop is set to auto, the animation straight-up doesn't play. I think it's getting stuck on the first frame (the character remains static while idling). Interestingly enough, if the crouch code is commented out, holding the crouch button will make it play while it's being held, but it won't play on its own. And to sort of piggy-back off of this:

How would I add other idle animations? I got a few idle flourishes (those idles that play every so often when you don't do anything for a bit, you know the ones) and I have no clue how I would go about getting those working. I got them set to an AtEnd transition on the state machine that goes back to the main idle, but that's it. I'm assuming I would use a Timer node for that, but again, I'm not sure what needs to be done for it.

Landing animation: I got a landing animation that should play only if the player collides with the ground without any input (moving, attacking, etc.), but should also be canceled either early or entirely should the player decide to do something. I've tried a bunch of different methods, from forcing the state machine to go from 'fall' to 'land' then 'idle,' checking what the current animation is, and even attempting to make a check if the player is in the air then grounded, but so far, nothing's worked out. It looks like it'll play for a split second at the start of a jump, but as you probably guessed, that's not where it's supposed to happen. As of now, the player goes straight to their idle from the fall animation. State machine for it is set up like so: Jump -> JumpPeak -> Fall -> Land -> Idle. 'JumpPeak' and 'Land' have AtEnd transitions and 'Fall' can go into different states depending on what's being pressed.

Player starts the scene in their jump animation: This one's a bit weird. If the scene starts and the player is airborne, they'll fall downward starting in the jump state, immediately transition to the JumpPeak and then finally the fall, instead of just being in the fall state the whole time. AFAIK, it only happens when the scene starts and they're in the air. Every other time the player goes airborne afterwards, everything works as intended. I really don't know what's causing this.

'JumpPeak' plays a little late: Admittedly this isn't that big of a deal, but might as well try asking anyway. There's a brief moment where the player is suspended in the air at the peak of their jump before falling. Ideally, this is where the 'JumpPeak' animation would play, but right now, it plays when the player starts descending. Again, not that big a deal, but I do think it would look nicer if it played earlier during the actual peak. I have no idea how to do that though.

Again, I apologize for the giant post and for asking so many questions. Any help/feedback is incredibly appreciated! Please let me know if something needs more clarification.

PhantomFox128

Bumping this as I haven't gotten an answer yet and still haven't figured it out.

TwistedTwigleg

1 Idle animation doesn't play

If the animation is getting stuck on the first frame, my hunch is that stateMachine.travel("Idle"); is being called repeatedly and that is resetting the animation, or another animation is being called before it and then the animation is changed to idle right after, leading it to be reset.

I would add a condition that checks if the animation is already set to idle and only play idle if the animation is different. If that does not work, then I'd try printing the name of the animation state right before calling idle and see if it's being set to something else.

2 How would I add other idle animations

If it was me, I'd count how many times the idle animation has looped and then after a certain number, play one of the special idle animations instead. However, looking quickly through the code for AnimationTree's, it looks like there isn't a good way to tell if an animation just finished.

In this case, I'd use a timer instead. Something like this (pseudo code):

var time_spent_in_idle = 0
const IDLE_CHANGE_ANIM_TIME = 2
var special_idle_anim_names = ["IdleStand_Alt01", "IdleStand_Alt02"]

func _process(delta):
	# other code
	if (state_machine.get_current_node == "IdleStand"):
		time_spent_in_idle += delta
		if (time_spent_in_idle >= IDLE_CHANGE_ANIM_TIME):
			var random_idle_index = round(rand_range(0, special_idle_anim_names.size()-1))
			state_machine.travel(special_idle_anim_names[random_idle_index])
	else:
		time_spent_in_idle = 0

3 Landing animation

Not sure on this one, to be honest. It might be the transitions that are causing the issue. You could try calling state_machine.stop() right before changing states to see if that helps, but I'm not sure why it would be being called.

Another thing that potentially, maybe, could be causing the issue is the use of is_on_floor, as it may be that the time between the jump and _physics_process is where the animation is changing. You could try adding a grounded boolean in _physics_process, setting it to is_on_floor right after calling move_and_slide, and use that instead of is_on_floor and that might help?

4 Player starts the scene in their jump animation

Maybe a transition to the jump animation is forcing it to play? I don't see anywhere in code that would trigger it automatically.

5 'JumpPeak' plays a little late

You could try transitioning to JumpPeak right when the velocity goes from low to high (I.E the player is no longer ascending) but I have no idea how hard that would be to implement.

Before trying any of the suggestions, I would highly recommend making a backup of the project! All of that said: I haven't used the built-in animation state machine myself, so I'm mostly just making guesses based on my knowledge in other Godot areas, but it probably means I'm wrong on several points and I wouldn't want you to lose anything.

PhantomFox128

@TwistedTwigleg said:

1 Idle animation doesn't play

If the animation is getting stuck on the first frame, my hunch is that stateMachine.travel("Idle"); is being called repeatedly and that is resetting the animation, or another animation is being called before it and then the animation is changed to idle right after, leading it to be reset.

I would add a condition that checks if the animation is already set to idle and only play idle if the animation is different. If that does not work, then I'd try printing the name of the animation state right before calling idle and see if it's being set to something else.

I just figured this one out and I'm really embarrassed to say it. Turns out I had the name spelled wrong in the code the whole time. Should've been 'IdleStand' instead of just 'Idle.'> @TwistedTwigleg said:

3 Landing animation

Not sure on this one, to be honest. It might be the transitions that are causing the issue. You could try calling state_machine.stop() right before changing states to see if that helps, but I'm not sure why it would be being called.

Another thing that potentially, maybe, could be causing the issue is the use of is_on_floor, as it may be that the time between the jump and _physics_process is where the animation is changing. You could try adding a grounded boolean in _physics_process, setting it to is_on_floor right after calling move_and_slide, and use that instead of is_on_floor and that might help?

Edit: Seems like it also fixed this one too! Although it does look like it'll still play for a split second at the start of a jump. I don't know how I would test it to prove that though.

TwistedTwigleg

@Azerkit said:

@TwistedTwigleg said:

1 Idle animation doesn't play

If the animation is getting stuck on the first frame, my hunch is that stateMachine.travel("Idle"); is being called repeatedly and that is resetting the animation, or another animation is being called before it and then the animation is changed to idle right after, leading it to be reset.

I would add a condition that checks if the animation is already set to idle and only play idle if the animation is different. If that does not work, then I'd try printing the name of the animation state right before calling idle and see if it's being set to something else.

I just figured this one out and I'm really embarrassed to say it. Turns out I had the name spelled wrong in the code the whole time. Should've been 'IdleStand' instead of just 'Idle.'

I've accidentally misspelled stuff and not realized it far too often! At least it was something easy that ended up to be the fix, instead of it being an undiscovered bug or something :smile: