Animation CAPTURE mode does not work in AnimationTree

[kingoftheconnors]

Godot version

3.3.2

System information

Windows 10, GLES3, Intel HD Graphics 4600

Issue description

I created an animation using the CAPTURE transition mode. I expected this to work in an AnimationTreeStateMachine, with the captured tween starting at the node's position when the animation starts. Instead, it acts just like a regular transition mode, causing the property to be insta-set to the first key.

Steps to reproduce

When run as an AnimationPlayer using $AnimationPlayer.start("animation"), it works as expected; however, when placing the animation in an AnimationTreeStateMachine and using $AnimationTree['parameters/playback'].travel("animation") it does not do any capturing and starts the node property at the first key.

Godot.Engine.-.AnimationTreeProblem.-.Test.tscn._.2021-11-18.21-33-50.mp4

It looks as though the AnimationTree does not handle the CAPTURE mode.

Animation_Player.cpp, line 400:

case Animation::TYPE_VALUE: {

	Map<StringName, TrackNodeCache::PropertyAnim>::Element *E = nc->property_anim.find(a->track_get_path(i).get_concatenated_subnames());
	ERR_CONTINUE(!E); //should it continue, or create a new one?

	TrackNodeCache::PropertyAnim *pa = &E->get();

	Animation::UpdateMode update_mode = a->value_track_get_update_mode(i);

	if (update_mode == Animation::UPDATE_CAPTURE) {
		if (p_started || pa->capture == Variant()) {
			pa->capture = pa->object->get_indexed(pa->subpath);
		}

		int key_count = a->track_get_key_count(i);
		if (key_count == 0)
			continue; //eeh not worth it

		float first_key_time = a->track_get_key_time(i, 0);
		float transition = 1.0;
		int first_key = 0;

		if (first_key_time == 0.0) {
			//ignore, use for transition
			if (key_count == 1)
				continue; //with one key we can't do anything
			transition = a->track_get_key_transition(i, 0);
			first_key_time = a->track_get_key_time(i, 1);
			first_key = 1;
		}

		if (p_time < first_key_time) {
			float c = Math::ease(p_time / first_key_time, transition);
			Variant first_value = a->track_get_key_value(i, first_key);
			Variant interp_value;
			Variant::interpolate(pa->capture, first_value, c, interp_value);

			if (pa->accum_pass != accum_pass) {
				ERR_CONTINUE(cache_update_prop_size >= NODE_CACHE_UPDATE_MAX);
				cache_update_prop[cache_update_prop_size++] = pa;
				pa->value_accum = interp_value;
				pa->accum_pass = accum_pass;
			} else {
				Variant::interpolate(pa->value_accum, interp_value, p_interp, pa->value_accum);
			}

			continue; //handled
		}
	}

	if (update_mode == Animation::UPDATE_CONTINUOUS || update_mode == Animation::UPDATE_CAPTURE || (p_delta == 0 && update_mode == Animation::UPDATE_DISCRETE)) { //delta == 0 means seek

		Variant value = a->value_track_interpolate(i, p_time);

		...

Animation_Tree.cpp, line 937:

case Animation::TYPE_VALUE: {
	TrackCacheValue *t = static_cast<TrackCacheValue *>(track);

	Animation::UpdateMode update_mode = a->value_track_get_update_mode(i);

	if (update_mode == Animation::UPDATE_CONTINUOUS || update_mode == Animation::UPDATE_CAPTURE) { //delta == 0 means seek

		Variant value = a->value_track_interpolate(i, time);

		...

Both use a->value_track_interpolation(), but the AnimationTree does not intercept the request if p_time < first_time_key like the AnimationPlayer does.

Minimal reproduction project

AnimationTreeProblem.zip

[TokageItLab]

May be related by #48432.

[akien-mga]

It's a stretch 2+ years later, but in case you still have a project trying to make use of CAPTURE in 4.x, could you assess whether #86715 solves the issue the way you would expect it to? You can test the PR by download a build (artifact) for your platform from the "Checks" (CI) tab.

[kingoftheconnors]

@akien-mga I'll do it tonight!

[kingoftheconnors]

@akien-mga No, it's not fixed. And it may be because capture node isn't working for AnimationPlayer either. So it's just straight-up broken.

_.TestAnimate.tscn.-.TestAnimationCapture.-.Godot.Engine.2024-02-09.09-09-09.mp4

Note, if I go back to 4.1 and test it out, the AnimationPlayer IS working with capture (although AnimationTree isn't), so it must have been broken by this commit or a recent one.

TestAnimate.tscn.-.TestAnimationCapture.-.Godot.Engine.2024-02-09.09-12-08.mp4

[TokageItLab]

@kingoftheconnors You should read the PR description. Currently, the editor does not playback the capture so you must use capture() method in script to interpolate capture frame.

[kingoftheconnors]

@TokageItLab Ah, thanks!

I've tested it out using capture(), and while running AnimationPlayer directly from a script DOES work, AnimationTree does not:

extends Timer

var is_left : bool = false
func _on_timeout() -> void:
	var animator : AnimationPlayer = get_node("../AnimationPlayer")
	var animation_tree : AnimationTree = get_node("../AnimationTree")
	if is_left:
		#animator.play_with_capture("go_right") #This DOES work
		animator.capture("go_right", 1.0)
		animation_tree['parameters/playback'].travel("go_right")
	else:
		#animator.play_with_capture("go_left") #This DOES work
		animator.capture("go_left", 1.0)
		animation_tree['parameters/playback'].travel("go_left")
	is_left = !is_left

TestAnimationCapture.DEBUG.2024-02-09.14-36-55.mp4

I also tested it with start(), instead of travel() and it was the same deal.

[TokageItLab]

Use animation_tree.capture(), not animation_player.capture() if you want to use AnimationTree.

[kingoftheconnors]

Ah, that works!

I can confirm this issue is fixed. I'll close this.