IK preview does not work

[tamagos]

Godot version

Godot_v4.0-rc1_mono_win64.zip

System information

Windows 10

Issue description

in editor can not preview the IK of skeletonIK3D,
worked in December betas

Steps to reproduce

add skeletonIK3D node
setup
click play IK
click target node3D
IK preview mode no longer active so can not see results of moving it

Minimal reproduction project

N/A

[lyuma]

I'm surprised this regressed since I don't think there's been any work done on the IK node, but I am looking into issues related to SkeletonIK3D so I'll include this in my testing.

[dszhblx]

Although SkeletonIK3D is not working right now, I also encountered this problem

[lobziq]

Can confirm, switching from SkeletonIK3D to any other node results IK solver stop playing (in editor).

[lobziq]

@tamagos @dszhblx ive slapped a quickfix as editor tool, attach this to your SkeletonIK node and click "playing" checkbox in properties

@tool
extends SkeletonIK3D

@export var playing: bool = false


func _process(delta):
	if not Engine.is_editor_hint():
		return
		
	if self.playing and not self.is_running():
		self.start()

	if not self.playing and self.is_running():
		self.stop()

[dszhblx]

@Calinou Since you guys decided that Godot 4.0 includes SkeletonIK3D which works fine, this little bug should also be fixed in Godot 4.0.Thanks!

[RNubla]

This issue still persist in 4.0😢 but hopefully this gets fixed on the next update 🤞

[DillonSteyl]

@lyuma

I'm surprised this regressed since I don't think there's been any work done on the IK node, but I am looking into issues related to SkeletonIK3D so I'll include this in my testing.

In case you're still looking at SkeletonIK3D issues, I just had a brief look into this.

void SkeletonIK3DEditorPlugin::edit(Object *p_object) {
	if (p_object != skeleton_ik) {
		if (skeleton_ik) {
			play_btn->set_pressed(false);
			_play();
		}
	}

If the edit method is called on the SkeletonIK editor plugin with a nullptr as the object, the SkeletonIK is disabled.
If this particular code is removed, the issue goes away - however this hasn't been touched in years. So it almost feels like this was originally the intended behaviour?

It does look like there was some recent work done in editor_node.cpp. In this particular case, the method is called by the hide_unused_editor method:

void EditorNode::hide_unused_editors(const Object *p_editing_owner) {
	if (p_editing_owner) {
		const ObjectID id = p_editing_owner->get_instance_id();
		for (EditorPlugin *plugin : active_plugins[id]) {
			_plugin_over_edit(plugin, nullptr);  // <-- this is it
		}
		active_plugins.erase(id);

I'm not sure if its as simple as removing the first part of the edit method on the SkeletonIK editor plugin - that seems to fix the issue, but I'm not sure if it would have unintended side effects.

[lyuma]

Here's another workaround you can use today (kind of the Blender style approach, like how you'd do pose mode while editing a mesh)

basically select two nodes, and then you get to keep the toolbar item for the SkeletonIK3D and it keeps updating.
We could theoretically mention this in the documentation. unfortunately it's not so obvious. I'll think what to do.