OKay, I've attached an image which is hopefully good enough to illustrate what I'm thinking about blendshapes.
Unless, I'm missing something, the current interpolation method is described by the first (left) diagram.
Is there a way through which the user can “define” a mid step (green) so that the transition from A to B isn't described by a straight linear translation of the geo's points?
Of course, ideally the interpolation would be a bezier curve with editable ctrl points.
You can't have organic looking deformations, often used in facial animation, aided by blendshapes that are linear.
Finding out that's already possible to achieve this, would be great news for me as I'm planning to dive into facial rigging/animation sometime soon.
Cheers!
edit: I know this is not a trivial issue, but it has been done apparently. [stargrav.com]
And this is the tool in action:
https://vimeo.com/265674660 [vimeo.com]
Let's talk Blend Shapes
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Thanks for your input guys. Unfortunately, blend shapes to be used in a facial rig or any other animation setup, is a complicated issue. The images I sketched above were to represent conceptually a very simple case, this is hardly ever happening in practice and this is the crux of the matter: figuring out the actual path the points take from shape A to shape B in order to have a believable transformation. And “believable” is a hard nut to crack because from A to B a point can take many paths, the start and the end being always the same, what's happening in the middle being the thing that makes a difference, which is why the user intervention is necessary in order to provide the system with at least one mid-step (like a sub-sample) so that it doesn't take another possible path.
If you go to the stargrav link and download the docs (a .zip file) you'll be able to understand the problem that they try to solve and then how they've approached it.
I'm figuring that this is something only the devs can tackle.
If you go to the stargrav link and download the docs (a .zip file) you'll be able to understand the problem that they try to solve and then how they've approached it.
I'm figuring that this is something only the devs can tackle.
Edited by anon_user_89151269 - April 27, 2018 03:54:52
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- Aizatulin
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Hi,
you can use cubic bezier curves to interpolate two points, if you have something like a direction for both points. But getting the direction automatically, seems to be a very hard problem for a general case (sometimes the normal can be good choice perhaps). If you have multiple targets, the result may depend on the order, how you apply each morph. In the linear case the result is independent from the order.
you can use cubic bezier curves to interpolate two points, if you have something like a direction for both points. But getting the direction automatically, seems to be a very hard problem for a general case (sometimes the normal can be good choice perhaps). If you have multiple targets, the result may depend on the order, how you apply each morph. In the linear case the result is independent from the order.
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- matthias_k
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as Aizatulin said, direction/orientation is important to know.
Maybe you'll need at least 3 shapes.
or try something like this:
https://vimeo.com/251487780 [vimeo.com]
smooth it later, then you have enough informations :-)
Maybe you'll need at least 3 shapes.
or try something like this:
https://vimeo.com/251487780 [vimeo.com]
smooth it later, then you have enough informations :-)
English is not my native language, sorry in advance for any misunderstanding :-)
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- matthias_k
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- matthias_k
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Spline blend with before and after helper…
play with the before and after helper to change the blend curves.
based on:
https://vimeo.com/251487780 [vimeo.com]
play with the before and after helper to change the blend curves.
based on:
https://vimeo.com/251487780 [vimeo.com]
Edited by matthias_k - May 8, 2018 16:43:30
English is not my native language, sorry in advance for any misunderstanding :-)
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- anon_user_89151269
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Thanks, guys. It'll take some time to thoroughly verify these solutions, as I intend to use a real case scenario, i.e a face with shapes, to see which and how well they perform. Also, browsing through those videos, I noticed at a glance that there are a few things I'm not familiar with yet, so figuring those out will come with additional cost.
Cheers all!
Cheers all!
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