timeScale -1 not working

[lijualivenow]

model.setAttribute('animation-mixer', {timeScale: -1})

not working

timeScale: 0 and 1 is working

[dirkk0]

It does work for me: https://mech-walker.glitch.me/

via https://glitch.com/edit/#!/mech-walker?path=index.html%3A20%3A15

[kylebakerio]

timescale 1 set manually for me doesn't play my animation. Had to set to .99.

[kylebakerio]

-.5 is not working for me right now. Unfortunately, glitch seems to be experiencing an error and I cannot load the glitch code, either.

[kylebakerio]

I see that that code, by looking in sources, is using the dist version of aframe-extras, which doesn't include support for startFrame. Sadly, I need to play a certain animation backwards, and my artist has encoded my animations as different frame sections. It seems that negative timeScales have problems in the undistributed version, but the current dist version doesn't support startFrame. Nothing to do but ask the artist to break these up into different models or learn how to save them as different animations.

[lijualivenow]

I did reverse animation using ThreeJS

here is my code

const nextButtonComponent = () => ({
  init() {
    const scene = this.el.sceneEl
    const animationList = ['idle', 'pockets', 'hiphop', 'chicken']
    const model = document.getElementById('model')
    const nextButton = document.getElementById('nextbutton')
    const prevbutton = document.getElementById('prevbutton')
    const clock = new THREE.Clock()
    let deltatime = clock.getDelta()
    let modelMesh
    let mixer
    let clips
    nextButton.style.display = 'block'
    prevbutton.style.display = 'block'
    let idx = 1  // Start with the 2nd animation because the model starts with idle animation

    function playAnimationByIndex(mIndex) {
      if (modelMesh) {
        const clip = THREE.AnimationClip.findByName(clips, animationList[mIndex])
        const action = mixer.clipAction(clip)
        action.reset()
        action.paused = false
        action.setLoop(THREE.LoopOnce)
        action.clampWhenFinished = true
        action.timeScale = 1
        action.play()
        action.enable = true
      }
    }

    function playReverseAnimationByIndex(mIndex) {
      if (modelMesh) {
        const clip = THREE.AnimationClip.findByName(clips, animationList[mIndex])
        const action = mixer.clipAction(clip)
        action.reset()
        if (action.time === 0) {
          action.time = clip.duration
        }
        action.paused = false
        action.setLoop(THREE.LoopOnce)
        action.timeScale = -1.0
        action.play()
      }
    }

    function nextAnimation() {
      if (modelMesh) {
        playAnimationByIndex(idx)
        idx = (idx + 1) % animationList.length
      }
    }

    function reveseAnimation(){
      playReverseAnimationByIndex(idx)
    }

    function update(event) {
      if (mixer) {
        deltatime = clock.getDelta()
        mixer.update(deltatime)
      }
    }
    nextButton.onclick = nextAnimation
    prevbutton.onclick = reveseAnimation

    model.addEventListener('model-loaded', (e) => {
      modelMesh = model.getObject3D('mesh')
      mixer = new THREE.AnimationMixer(modelMesh)
      clips = modelMesh.animations
    })
    scene.addEventListener('updated', update)
  },
  tick(time) {
    this.el.sceneEl.emit('updated')
  },
})

export {nextButtonComponent}

[koktavy]

In the animation-mixer update method, parameter changes besides clip only apply to the active actions. The changes should be applied just before playing other clips in playAction but it seems that isn't happening correctly.

One workaround is to remove the mixer and set it again:

animatedEl.removeAttribute('animation-mixer')
animatedEl.setAttribute('animation-mixer', 'clip: *; timeScale: -1; clampWhenFinished:true; repetitions:1;')

[vincentfretin]

Is this still an issue? If yes, do you have a fix? Somebody want to create a PR?

[vincentfretin]

Can somebody create a glitch with a reproducible case if this is still an issue? Thank you.

[dirkk0]

No, it does work, see my glitch here: https://mech-walker.glitch.me/ The Mech walks backwards.

[vincentfretin]

Thank you @dirkk0 I'll close then. If anyone still has an issue, please create a new issue with a reproducible case that use a master build on glitch.

[v5ma]

Here is an example that works, and an explanation for why it works. GLBanireverse