Skinned mesh renderer lags behind

[SwagAccount]

Describe the bug

I am moving an object using my follow attachment script.
As a child the object has an arm which uses a skinned mesh renderer.

That mesh renderer and any other skinned mesh renderers as a child will always lag behind. In the scene view this doesn't occur

To Reproduce

1. Move an object using pre render
2. Have a child with a skinned mesh renderer
3. Do the hanky panky

Expected behavior

Not lagging behind

Media/Files

https://github.com/SwagAccount/the_second_coming_of_k/blob/main/code/FollowAttachment.cs

https://github.com/Facepunch/sbox-issues/assets/160753124/36c24333-efbf-4deb-80b5-52d698b4b302
^ I have also attached a normal model to show its not the script that is lagging behind.

Additional context

No response

[garrynewman]

Does the same occur if you do it in OnUpdate?

[SwagAccount]

Yes, ive tried all updates

[SwagAccount]

I've now changed my system so the arms attach to the camera and the ik is to move the hand to the gun, still the same effect.

[PolSpock]

Hi,

Since this commit, i guess cause i didn't have this issue yesterday,
it looks like the GetAttachment position is now incorrect during the first tick :

I am currently investigating to find a scenario to reproduce the issue. I will edit this comment

Edit :

1. Create GameObject parented to the head bone :

var goHat = new GameObject();
goHat.SetParent( bodySkinnedModelRenderer.GetBoneObject( bodySkinnedModelRenderer.Model.Bones.AllBones.Where( x => x.Name.Equals( "head" ) ).FirstOrDefault() ));
goHat.Components.Create<MyAttachment>();

2. Create MyAttachment Component:

public class MyAttachment : Component
{
	[Property] public SkinnedModelRenderer SkinnedModelRenderer { get; set; }

	public SkinnedModelRenderer GetPlayermodel()
	{
		return GameObject.Components.GetInAncestors<SkinnedModelRenderer>();
	}

	protected override void OnStart()
	{
		base.OnStart();

		SkinnedModelRenderer ??= GameObject.Components.GetOrCreate<SkinnedModelRenderer>();

		var model = Cloud.Model( "darg/santahatprop" );
		SkinnedModelRenderer.Model = model;

		Transform.Position = GetPlayermodel().GetAttachment( "hat" ).Value.Position;
		Transform.Rotation = GetPlayermodel().GetAttachment( "hat" ).Value.Rotation;

	}

	protected override void OnUpdate()
	{
		base.OnUpdate();

		// TOGGLE COMMENT / UNCOMMENT
		//Transform.Position = GetPlayermodel().GetAttachment( "hat" ).Value.Position;
		//Transform.Rotation = GetPlayermodel().GetAttachment( "hat" ).Value.Rotation;
	}
}

3. See bug OnStart:

2024-05-09.19-17-55.mp4

[garrynewman]

I made a change that should fix the first frame being wrong position.

This won't fix the OP request though. This is a chicken and egg problem, and the only way I can see to fix it would be to allow you to set IK bones to offsets from GameTransforms.

[PolSpock]

I made a change that should fix the first frame being wrong position.

This won't fix the OP request though. This is a chicken and egg problem, and the only way I can see to fix it would be to allow you to set IK bones to offsets from GameTransforms.

Nothing change for the sub issue (my build id : 14327656), i have created a issue in order to stop off topic for this issue : #5493

[SwagAccount]

Is there a reason that the skinned mesh renderer is updating after the camera, that is the only understandable thing that is happening. I can make any normal model renderer I want follow something by setting the position and it's perfect, but as soon as I change the model renderer to a skinned renderer it lags a frame behind.

[SwagAccount]

Ok strange thing happening. When I move the gun around it leaves a ghost of an arm that is perfectly connected to the gun, how I want, whilst the rest of the arm is stuck a frame behind. However, when I record it the ghosting doesn't appear in the recording. What on earth is happening.

[SwagAccount]

Ok, solved the issue by using SetIK and using the correct naming for parameters in anim graph.
https://cdn.halend.dev/retro/1105/sbox-dev_1xz8x0h9y0.png
if ( IkRightHand.IsValid() && IkRightHand.Active ) Target.SetIk( "hand_right", IkRightHand.Transform.World ); else Target.ClearIk( "hand_right" );