View Full Version : Endomorphs and bullet softbodies.

06-25-2014, 06:32 AM
Hello wise people!

I would like to know if this is an impossibility right now or if I am just being stupid. I am trying to make some softbody dynamics using Bullet, and at some point the object should morph into a new shape, while keep doing its softbody thing.

So I applyed Bullet to the object, Deforming type, added some forces and I have my object deforming and blowing in the "wind". All fine there. Then I applied MorphMixer and made some keys for the endomorph. I was hoping that the object would morph and still blowing in the wind, but the morphing is not working.

I can make the morph right at the beginning, i. e., if I make the morph 100% at frame 0 Bullet will pick it up and use that shape for the softbodies. But it will not do it if I apply the morph in the middle of the simulation.

So, is that an impossibility and I am once again let down by the inconsistencies of this program or am I being thick and a dumbass?

Thank you,

06-25-2014, 06:47 AM
I *believe* that bullet does its thing after examining the shape at the start... after that, its all down to the bullet deformer. If that is indeed so, then what youd wanna do would be to save out the softbody stuff to an mdd, bring that, plus the morf into nodal, and add the 2 displacements together there.

06-25-2014, 09:43 AM
Thank you for your reply, RebelHill. I see what you mean with your solution, but that will not work here, as I would like to morph the object and continue to get the bullet softbody effect to be applied depending on the new shape, so it would make a different simulation. Basically, I would like to have some goo-like substance (imagine something nice, like nasal mucous!) to blow in the wind, and then extend into tendrils (by morphing) which would continue to be deformed by wind, so the softbody effect has to be applied after the morph has taken place to take in consideration the new shape.

06-25-2014, 09:48 AM
Ok... get what you mean.

In which case (assuming what I said before regarding bullet is correct), your only option is gonna to either make up your own "wiggle" deformer via nodes which can work on top of the morf... or, go back to LWs regular ol softFX, which does "see" and work "over" morf displacement.

06-25-2014, 10:31 AM
Bone dynamics?

06-25-2014, 05:35 PM
Well, I see, thanks anyway.

Jeric, bone dynamics could work for the wiggling, but I don't think they would stretch automatically. It would be a pain to resimulate and stretch the bones by hand everytime. Plus, I don't even remember how to set up those... was it with IKBoost? Jesus, talk about a leap to the past!

It's a pity that everytime I get back to Lightwave in order to make something because "Hey, maybe I can do this really fast in Lightwave! Like in the good old times!", every logic thing doesn't work as it should for lacking of communication. I'm just disappointed. One of these days it was a problem with particles: I needed to make a waterfall. The Realflow part was actually pretty straight forward... then getting the data into Lightwave was a small nightmare. Of course later I discovered I would have to have the patience of a saint in order to load 8 million particle clouds into Lightwave!

06-25-2014, 05:51 PM
I'll take your word for it, because the words "bone dynamics" is about all I know about bone dynamics.

06-26-2014, 03:51 AM
Maybe meta link and meta link morph could help out here.

06-26-2014, 07:23 AM
It's simple to get morphs working with Bullet softbodies. Turn up shape retention to say 50% and turn Shape Lock Translate and Rotation on. The Shape retention makes it wobble back to its shape (morphed and not morphed), and Translate and Rotation locks it in place, otherwise the body will slowly wiggle away from where it was originally. Also, turn down linear stiffness as this inhibits the stretching/compressing of the surrounding polygons. Here is an example of a repeating morph and bullet reacting to it.

06-28-2014, 09:49 AM
Hi Dodgy!

Thank you for your example. I didn't have time to try it while doing the shot, but now that I finished it (doing some other stuff instead of what I wanted originally) I tryed your method. It almost works, good finding! It actually works even without Lock Translate/Rotation. However it doesn't allow the morph to go all the way through to the end and it's difficult to get the same simulation you had initially. I mean, in order to get the full morph "Shape Retention" would have to be 100%, and in hat case it just giggles but doesn't deform. When putting it at 50% it kind of works, but the morph only goes to 50%, obviously, and the simulation looses more than 50% of it's power (I'm saying this because it doesn't look a linear loss to me, but that may be an illusion).

Anyway, with this it's actually true that you can have morphs and softbodie dynamics with Bullet, but at the cost of some extra time re-simulating with parameters that go out of scale and doesn't give the results expected originally.

06-28-2014, 10:40 AM
VirtualFM, sims not my thing but here are some ideas pitched.

No way you have a MDD playing (morph animation baked to MDD) and have Dynamics see the object like that?

Another pitch would be to check how the Morph Target option (Where you choose a scene item with the same topology in a drop down menu and the Morph amount in the Deform Tab) stacks up with the other stuff. So you could be running a simulation and morph into the other snotty thing.

Last, save two MDDs of the object being affected by wind in both shapes and mix them in Nodal Displacement.

Good luck