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Can a slight flexi type of movement be built into a mesh using weighting?


Violaine Villota
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First off, I'm a huge newb to mesh in SL. I haven't tried making any wearable meshes yet, though I've gone through quite a few tutorials on it because I needed small invisible mesh parts to make my Bento flexi wings attach and animate.
One animation I saw on YouTube showed a cat or tiger shaking it's head, and it looked a lot like the ears had a bit of flex in the ears when that animation happened.
Was that an optical illusion, or can some amount of flexibility be built into meshes using weight maps?
One of the big reasons I still make my wings flexi is I love the movement that only flexi prims can provide - or so I'm assuming. But if I can achieve that affect without having to animate the flexiness for each set I may change things...

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On 12/23/2018 at 5:55 AM, Violaine Villota said:

Was that an optical illusion, or can some amount of flexibility be built into meshes using weight maps?

Using bento features like the earbones you can do that, but you're limited to 1) the available extra joints 2) the animations you will make in order to get such result

Flexi can't be done with mesh in SL, what you've seen in that video is a feature-complete software animation that either implemented dynamics on joints or soft-bodies on mesh (not to mention the possible motion on the fur which is yet another thing)

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Thanks Optimo, maybe it was video from outside of SL that I'm remembering. What I would want to add flex to would be wings, or at least, wing tips using the bento wing bones. I think there are enough joints for that, but maybe what I thought I remembered seeing is impossible. If there were a way to weight the bones themselves too, so that some movements would affect lightweight bones differently than heavy ones that would be cool, but doesn't sound like it can happen.
In all truth I'd rather at least get that damn online DMCA form available before we get any other new features anyway.

 

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On 12/29/2018 at 2:26 AM, Kyrah Abattoir said:

There is no "lag" bones in SL, so the only way is to fake it though animation. It can look allright but most likely won't be context sensitive.

Thanks Kyrah. For some reason I'm not getting all my notifications either in my email or here in my dashboard, so I didn't see your reply til now.

Ok, so I guess I'm confused about how weight maps work then. It seems like logically, let's say if I weighted a flat panel  to a straight bone and weighted it so that both ends are weighted to really stick, and then towards the middle hardly any weighting, that when that bone moves the middle should bow as if it were fabric.

But so, SL doesn't have mesh physics that react that way yeah? Weighting is only for how fitted meshes are to either an avatar's skin or bones and if an area is not weighted it just doesn't respond to appearance sliders and avatar animations yes? 

Then I guess my next question would be if I could copy my current wing bone animations to the hind bones if I want to make the wings mesh and utilize an upper and lower set of bones.

 

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The way weighting works is that the new position of the vertex is based on a weighted average transform of all the bones affecting it. if a bone has 10% influence and another 90%, the 90% bone will influence the vertex's new position the most, and the 10% the least.

You'd think that would allow to create some sort of gravity effect, but in practice it doesn't really work.

Also you can't have unweighted vertices, any and all vertices have to be weighted to at least one bone and at most four.

Yes, to my knowedge you could use one of the extra bone sets (and the proper animations) to fake some sort of effect like that, do keep in mind that any of the supplementary bento bones you "recycle" like this can potentially conflict with other products.

Edited by Kyrah Abattoir
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3 hours ago, Fenix Eldritch said:

There a is fairly recent JIRA feature request that asked for something like this: being able to achieve a sort of flexi with rigged bones. Vir Linden showed interest and imported the request for future consideration. Here's hoping!

Ah! That would be fabulous! I won't hold my breath but I hope eventually this happens.

 

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I don't think so. As far as I'm aware (though I am inexperienced in this area), different weighting for up to four influencing bones is all SL will accept.

I suppose you could achieve this effect by creating an alternate set of animations which target only the desired bones (wings in your example) and have them mimic the base animation, but with whatever modification you wanted (such as appearing as if moving through fluid). And then upload that animation with a higher priority than the base. So then you could play the base animation as normal and then when the desired criteria is met, such as going under water, also play the alternate animation to basically override the wings.

Edited by Fenix Eldritch
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19 minutes ago, Violaine Villota said:

Now, when animating in Blender, is it possible to make the bones being animated behave as if in certain atmospheric conditions, like say, underwater so that if I move the wing bones at the base there is lag when the others move as if they are encountering wind resistance or water? 

As i said earlier, no lag bones. Bones are under an animation, or will not move, at all.

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13 minutes ago, Kyrah Abattoir said:

As i said earlier, no lag bones. Bones are under an animation, or will not move, at all.

Ah ok. I was hoping maybe there might be some trick to getting the bones to react a certain way in Blender similar to the existing joint limitations - I'm forgetting at the moment what the technical term is. That option you check so that the skeleton bones can only be positioned or animated in ways that are physically possible for the human body, it would be neat if there was one that could create drag of some kind.

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1 hour ago, Kyrah Abattoir said:

Looks like a curve constrained bone chain.

You mean the Bendy Bones video, or do you mean that's what I need to learn to make the animation I'm wanting?
Oh and now I know what I was trying to explain earlier - inverse kinetic bone constraints. Maybe there is some way I can utilize that to get the movement I want, but what I really wish is that it worked backwards - and not just the way that the forward kinetics would work because that makes all the child bones move along with it in a stiff way.
What I would like to be able to do, is move the first wing bones at the base and have the rest of the chain follow but as if the joints were slightly loose so the whole thing would curve.
It's possible there's something like that as an animation or plugin in a 3D marketplace to purchase, but then it might not work with Avastar and SL anyway. I came across one called "Tail Animator" sold in the Unity marketplace that looks just like what I would want to do, but I'm pretty sure it's not SL compatible.
Oh well! Thanks all for your help, I appreciate it.

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You can make your animations by using a IK spline attached to the bones chain and then setting the spline as dynamic. The animations will always be fixed and you still need to export them, but you can focus on the body animation to have such a setup chain physically animate in response to that motion without animating it directly. 

The Blender bendy bones are an internal feature of Blender, usually applied to and for cartoon characters. The approach that Blender gives the user to achieve this behavior is pretty easy and accessible as it requires one bone only and then turns that into a chain, but it's not a common feature in 3D packages in general, so figure in SL.

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5 hours ago, OptimoMaximo said:

You can make your animations by using a IK spline attached to the bones chain and then setting the spline as dynamic. The animations will always be fixed and you still need to export them, but you can focus on the body animation to have such a setup chain physically animate in response to that motion without animating it directly. 

The Blender bendy bones are an internal feature of Blender, usually applied to and for cartoon characters. The approach that Blender gives the user to achieve this behavior is pretty easy and accessible as it requires one bone only and then turns that into a chain, but it's not a common feature in 3D packages in general, so figure in SL.

@OptimoMaximo Thank you! So, would I just create a new bone chain that matches the existing bento wing bones and then parent that chain to the existing bones (like Medhue does with this elephant trunk here: 
or is an IK spline something different altogether that is not a duplicate set of bones that's matched up to the bento bones?

 

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8 hours ago, Violaine Villota said:

is an IK spline something different altogether

An IK spline is an IK system that works in couple with a spline or curve, so that the IK chain is dependent from the curve rather than its target. Curves can then be affected by physics by turning them dynamic or by manipulating the curve points using cluster handles (or what Blender calls Hooks). However, if what is shown in this video serves your purpose well, go ahead with it, it's simpler to set up

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On 1/5/2019 at 1:30 PM, Kyrah Abattoir said:

To clarify, this can be useful for making animations, but you can't export such structures to work in SL "as is". As i said before, no lag bones/jiggle bones/custom skeletons in SL.

Ah, well I assumed that the IK spline would just function to constrain the SL bones being animated, to get them positioned the way I want and then that's how it gets saved when exported. Is that not  how it would work? Would the spline only be useful for animations that stay in Blender or can be exported to other 3D programs?

 

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On 1/6/2019 at 10:39 PM, Violaine Villota said:

Ah, well I assumed that the IK spline would just function to constrain the SL bones being animated, to get them positioned the way I want and then that's how it gets saved when exported. Is that not  how it would work? Would the spline only be useful for animations that stay in Blender or can be exported to other 3D programs?

 

The IK spline itself stays within Blender. You can export the resulting animations to use them in SL, so that the motion you see in Blender as result from the IK spline setup can be used and played back in SL. 

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