How to reverse an animation

Troubleshooting graphics
1

Dear all,

I have a walk animation. But when the user press the key “S”, I would like to play the reverse walk animation. Can someone explain me how it is possible ?
I try with a animChannel.setSpeed(-1.0f) (negative value) but of course, it does not work…

Thank a lot.

2

http://hub.jmonkeyengine.org/javadoc/com/jme3/animation/AnimChannel.html

It looks like your only option is:

[java]
animChannel.setAnim(“TheBackwardsWalkAnimationIMadeInBlender”);
[/java]

=(

3

There is a loopmode called “Cycle” that the docs say “cycles back and forth”

I have no idea if trying to play the second half of this animation would work or if you could work thatin

My only other suggestion is to try to put a speed of -1

Neither of these are tested and just a guess

1 Like
4
@BigBob said: There is a loopmode called "Cycle" that the docs say "cycles back and forth"

I remember reading this a ways back, but could only make it go on the forth part >.<

I wonder if it actually does cycle into both directions… and how you would do that.

5

I have already tried the Cycle loopmode and to put the speed of -1. But no one works :frowning:

So, I think I will use the only solution:
[java]animChannel.setAnim(“TheBackwardsWalkAnimationIMadeInBlender”);[/java]

And see if there is a way to do it simply with Blender…

6

There is no way to play an anim backward.
The Cycle mode play the anim forward, then backward, but you can’t start with backward.

7

I think I did it in Monkey Trap but I feed my own frame time in for all of the animations… so I could run it in whatever direction I wanted.

8

Hi

pspeed that is brilliant idea :slight_smile:

-Tommi

9

hello,
sorry to dig this one
but how exactly do you “feed your own frame time” ??

I need to stp an anim (canceled by the user) to play it in reverse at the precise time it stopped

thanks

[edit: i guess setTime would do the trick, but a more user friendly way would be neat, I mean if it can play it backward that way, it should be the engine dealing with this with a LoopMode.Backward enum]

10

You can look at Monkey Trap if you really want to dig in:

But I suspect glancing at JME’s javadoc might be more helpful.
http://javadoc.jmonkeyengine.org/com/jme3/animation/AnimChannel.html

…see if you can figure out which method would set the animation time…

11

well I use setTime so far, but as I iterate over animation.speed, it seems to go faster, that’s why I think it would be better if the engine itself was dealing with this. thx anyway :smile:

12

I have no idea what that means.
animationTime -= tpf;
channel.setTime(annimationTime);
…not sure what the issue is.

13

reverses bone animation:

 Track[] tracks = myAminControl.getAnim("myAnim").getTracks();
    for (Track track : tracks) {

        Quaternion[] roatations = ((BoneTrack) track).getRotations();
        Vector3f[] scales = ((BoneTrack) track).getScales();
        Vector3f[] translations = ((BoneTrack) track).getTranslations();
        Vector3f tempVectror3f;
        Quaternion tempQuaternion;
        for (int i = 0; i < (roatations.length / 2); i++) {
            tempQuaternion = roatations[i];
            roatations[i] = roatations[roatations.length - 1 - i];
            roatations[roatations.length - 1 - i] = tempQuaternion;
        }
        for (int i = 0; i < (scales.length / 2); i++) {
            tempVectror3f = scales[i];
            scales[i] = scales[scales.length - 1 - i];
            scales[scales.length - 1 - i] = tempVectror3f;
        }
        for (int i = 0; i < (translations.length / 2); i++) {
            tempVectror3f = translations[i];
            translations[i] = translations[translations.length - 1 - i];
            translations[translations.length - 1 - i] = tempVectror3f;
        }
        ((BoneTrack)track).setKeyframes(((BoneTrack)track).getTimes(), translations, roatations, scales);
    }
2 Likes