Is it possible to create temporally-altered versions of versions of an animation in blender-avastar?

[miathea]

Hello everyone.

I made an animation for a right-handed person that performs complex hand movements, from which I'd like to also create a 'faster' and 'slower' animation so the animation as well. Is there a simple way to do this in blender-avastar please?

[RohanaRaven Zerbino]

Change FPS

 

[OptimoMaximo]

On 2/15/2021 at 11:54 AM, miathea said:

Hello everyone.

I made an animation for a right-handed person that performs complex hand movements, from which I'd like to also create a 'faster' and 'slower' animation so the animation as well. Is there a simple way to do this in blender-avastar please?

 

1 hour ago, RohanaRaven Zerbino said:

Change FPS

 

Yes it is possible, but changing fps, although achieving the desired result, isn't an optimal solution. File size may increase sensibly with higher fps, and there's a limit to file size for upload. 

The best way is to use the NLA editor, in which your animation turns into a box that you can scale in length, resulting in different animation speed. Or just plain old duplication of your animation clip and scaling the distances between the key frames. 

[RohanaRaven Zerbino]

On 2/18/2021 at 7:29 PM, OptimoMaximo said:

Yes it is possible, but changing fps, although achieving the desired result, isn't an optimal solution. File size may increase sensibly with higher fps, and there's a limit to file size for upload. 

Actually no, FPS manipulation has no impact on file size it is always the same, as FPS increase/decrease is not adding more info to the file it self. At least with .anim files, I don't know if there is difference with .bvh files. It might hit the time limit tho and go over 60 seconds.

 

[OptimoMaximo]

6 hours ago, RohanaRaven Zerbino said:

Actually no, FPS manipulation has no impact on file size it is always the same, as FPS increase/decrease is not adding more info to the file it self. At least with .anim files, I don't know if there is difference with .bvh files. It might hit the time limit tho and go over 60 seconds.

 

What you see is the result from Avastar "cleanup" process, which basically retimes everything to a fixed fps based length.

I wrote the export plug in for Maya that does anim file exports, believe me when I tell you that the file size increases. In my plug in I wanted a lossless output from my animations, so I did not include a under-the-hood optimization. There are 6bytes of data per frame, per joint, so mathematically fps has an impact: same visual speed of the animation, higher fps and there are physically more frames, therefore more data. If you need more details about the anim serialization feel free to ask.

[RohanaRaven Zerbino]

On 2/24/2021 at 10:15 PM, OptimoMaximo said:

What you see is the result from Avastar "cleanup" process, which basically retimes everything to a fixed fps based length.

I wrote the export plug in for Maya that does anim file exports, believe me when I tell you that the file size increases. In my plug in I wanted a lossless output from my animations, so I did not include a under-the-hood optimization. There are 6bytes of data per frame, per joint, so mathematically fps has an impact: same visual speed of the animation, higher fps and there are physically more frames, therefore more data. If you need more details about the anim serialization feel free to ask.

Let’s first define tools: I am using Blender Avastar for creating handmade animations since 2014.

Now, you are right, what I see is end result: all 3 animation files do have the same size. Whatever is going on under the hood of Avastar export process, that is the only option I have in Avastar and I have zero control over that. And if I understand well how you have made exporter in Mayastar, your users also have zero control over exporter.

On the other side, scaling (dope sheet frame stretching) IS adding to animation file size, as number of frames is actually increased. Shrinking frames in dope sheet is never good idea as all kind of mess up might be made. I am not using NLA as it doesn’t fit in my animation workflow, therefore I don’t have any tested and valid information on how animation file is changed with NLA length manipulation.

Not every animation is suitable for raw FPS manipulation for speed changing. Some of them will acquire an additional effort to make movement logical for chosen speed, but that goes with animation part of the process, not with tool part of the process.

So, to round up the answer to OP, I think it might be fair to just define things like this:

- If you are using Blender Avastar, experiment with FPS. Be careful not to exceed 60 seconds length limit.

- If you are using Mayastar be careful with FPS manipulation as it might increase animation file size, or choose some other method.

[OptimoMaximo]

7 hours ago, RohanaRaven Zerbino said:

Now, you are right, what I see is end result: all 3 animation files do have the same size. Whatever is going on under the hood of Avastar export process, that is the only option I have in Avastar and I have zero control over that. And if I understand well how you have made exporter in Mayastar, your users also have zero control over exporter.

Well, you actually have control over it, it's just not advertised. I've been helping with Avastar for the years before you even started, and have had extensive talks with the original dev. You can stop the automatic shrinking by setting a marker named 'fix' where you want the key frame to not be affected by the optimization, which means that if you add one of those markers to every single frame, you will basically get the raw data exported in full.

In MyAniMATE the control we are talking about is reversed in behavior, meaning that default export is raw data, and optionally there's a resampling attribute that gives the user the option to decide how much to shrink such animation data.