Animating objects on and off via scale


(Sehsucht) #1

Hey Everyone,

The support for Animation in sketchfab is really great so far, especially the support for pose morphs opens up a whole new world of possibilities. I ran however into a minor problem the other day. While trying to animate objects on and off via scale 1 to 0 there seems to be a weird interpolation happening when I view the animation in sketchfab. Instead of the object instantly disappearing sketchfab interpolates frames inbetween these two values and you can see the object scaling down. Is this happening because of discrepancies between the framrate of the animation and the framerate at wich the browser renders the animation?

Is there any way to force sketchfab into having objects disappear from one one frame to the other that you know of?

Thanks in advance,
yours truely


Multi-FBX + Animations
(Waleguene) #2

Hi @sehsucht,

Sorry about this issue, and thank you for reporting it.
Using a scale 0 is currently the only way to make an object disappear on Sketchfab, but it can lead to issues for a few edge cases.
We currently bake at 30 FPS so the interpolation is not instantaneous, but this is something we could improve for such cases.
Could you point us to the model you are talking about so that we can investigate?

Thanks!


(Sehsucht) #3

Hey Waleguene

Thanks for the fast reply. You can see it in effect in this animation for example - https://sketchfab.com/models/fda2189fddfc43d69ea2125e42d4db34

We tried workarounds such as moving the object in question into the very far distance from one frame to the other but that screws up the initial camera position when we upload animations. While this solution is not clean in any way it would help to have the ability to bring the camera towards point zero in the scene instead of having it frame the whole scene.

Again, I know its a very fringe case scenario, so thanks for your interest.

yours truely


(Rw36) #4

Hello -- Has this problem been fixed? I am having the same problem . . .


#5

There is some discussion here that might help:

https://forum.sketchfab.com/t/execute-function-based-on-animation-timeline-with-api/17507/4


(Rw36) #6

I am trying to morph between different CT data sets and need before and after data sets to "disappear" in order for it to display properly. I have tried everything suggested by you all for stepping the scaling from 0 to 1 between frames, but I still get these aberrant frames. Can you suggest anything I am doing wrong?

See 3:99 and 7:98 here:

https://sketchfab.com/models/a70648c353b144ffbe7430784ecf3029


#7

Hmm, @waleguene any idea? Maybe @shaderbytes or @paulchambers3d could help, too.


(Shaderbytes) #8

i work in blender and this is not solved perfectly via key frames and animation in blender.. i have done it and under certain conditions it works but sometimes it does not..


(Paulchambers3d) #9

I have experienced the same issue. This uses scale 1 on one keyframe and scale 0 on the next to make the words appear and disappear, but as others have stated some interpolation can be seen: https://sketchfab.com/models/f3cb7ff4c84a4ab49df3f69732e6a6ba


(Waleguene) #10

@rw36 @james @shaderbytes

I spent some time to fix this issue but it seems that it's not as trivial as expected.

We could do something to handle "Constant" interpolation mode, but it appears that most (probably all) the samples are not using this interpolation mode.

Any interpolation should work when the keyframes are set on two consecutive frames, since Blender is playing animations frame by frame (time independant).
On Sketchfab, we rely on time so we interpolate everything and it's not trivial to get the same result.

We are looking for a few improvements for our Blender processing, that might make this possible.