How to change from one animation to another instantly

blackvoyagegames

Hello Spine,

I'm having a frustrating issue where I want to change from one animation to another with mix duration = 0 but always end up having an inbetween-frame that looks jarring.

This is what it looks like

This is my code:

            public void SetAnimation(int trackIndex, AnimationReferenceAsset animation, bool shouldLoop)
            {
                if (animation == null)
                {
                    return;
                }

                this.ResetCompleteEvent();

                TrackEntry trackEntry =
                    this.ActiveSkeleton.AnimationState.SetAnimation(trackIndex, animation, shouldLoop);
                trackEntry.MixDuration = 0;
            }

For the record, the reason it works when I change animation to the one facing North (when his back is showing) is that we use a separate Spine skeleton entirely for animations where the back is showing. So then we just enable one gameobject and disable the other. But when the transitions happen within the same skeleton, it looks bad.

What can I do to make the transition less jarring?

Misaki

blackvoyagegames I'm sorry to hear you're having trouble. I am wondering what ResetCompleteEvent() is doing. I suspect that you are using an API there to back the skeleton to its setup pose and that causes it to look jarring. Could you please show us the code for that as well?

blackvoyagegames

Misaki

Thank you for the response Misaki! Sorry if my first post came across as negative.

The ResetCompleteEvent doesn't do much. It's a one-liner function that unsubscribes from a Complete event on the previous track. This complete event is otherwise responsible for automatically going back to an idle animation. This is the full code.

       public void SetAnimation(int trackIndex, AnimationReferenceAsset animation, bool shouldLoop)
        {
            if (animation == null)
            {
                return;
            }

            this.previousCompleteEventHandler?.StopListenToCompleteEvent();

            TrackEntry trackEntry =
                this.ActiveSkeleton.AnimationState.SetAnimation(trackIndex, animation, shouldLoop);
            trackEntry.MixDuration = 0;
        }

Does the complete event sound like it's the issue somehow? When doing mixduration = 0, it's not supposed to lead into an intermediate frame like I have, right? That's something I'm doing somewhere in the code.

Misaki

blackvoyagegames

Sorry if my first post came across as negative.

No need to apologize at all! I didn't take it that way. I just thought it was weird that it would behave like the animated GIF you attached when you set the mix duration to 0 and set the next animation by calling SetAnimation(), so I thought there should be something wrong with the code. I would appreciate it if you could provide a little more information as Harald asked.

Harald

@blackvoyagegames I'm afraid we need more information to be able to help. From where do you call your SetAnimation() method shown above?

In general whenever you see a single incorrect frame after skeleton changes, it could be due to a call being made too late in the update cycle, after SkeletonAnimation.Update() was already called which applies the animation frame, but before SkeletonAnimation.LateUpdate() which updates the Mesh according to the skeleton status. As a solution you can either call skeletonAnimation.Update(0) manually after your AnimationState.SetAnimation() call to apply the animation again, or ensure that your method is called before animations are applied (see the callback delegates here for more info).

blackvoyagegames

Thank you both of you, especially for the fast response. I managed to fix it by doing skeletonAnimation.Update(0) as Harald described. I'm going to look into it more properly in the future, but not when we have deadlines looming in a few days time!

Super happy I got to make the animations work just in time for the 29th. It significantly improves the feeling of the animation to see it happen instantly and (almost) without any dead frames.

Harald

@blackvoyagegames Glad to hear it helped, thanks for taking the time to get back to us. All the best with your deadline!