Using Vellium to create soft body for Shark

[Syrena]

Hello!

I've been trying to use Vellium to make my shark animation (bgeo) have some soft features in the body doing a basic swimming motion. I seem to have a problem

with the Vellium solver though... No matter the settings, the mesh just start to go wacky... . I followed the Sea Horse tutorial on the web using the Vellium Struts Softbody... did exactly what

the author did, but the shark is all chaotic... looks like crumpling paper. Something when I try the sea horse... using houdini 18.0 or 18.5 doesn't matter. Does anyone have a basic setup that will work for 

an animated shark object with basic swimming motion? The shark behaves fine when I don't add a constraint to apply the animation using pin target method... falls onto the grid and jiggles nicely. But when I try to apply

the animation via Vellium Constraint... it all goes nuts... even after adjusting stiffness, bending, iterations... :/

 

 

Edited April 19, 2021 by Syrena
more pics

[ryew]

It's hard to troubleshoot much without a scene to play with, but to be honest, vellum sounds like overkill for a shark swimming - if you just need the basic undulating motion of the tail and body twisting, why not try bend deformers?  Unless your shark is doing complex motion - in which case you're better off just rigging it - it seems a more low-tech approach should do the trick without all the simulation headaches.  Just my two cents - in my experience, it's unfortunately easy to overcomplicate things in Houdini

[skomdra]

Did you try to make remesh with a bigger value and then test your struts how do they behave? You can always use that low poly sim to drive your high poly model with point deform, do you know how to set this up? It is rather simple. For such a simple movement you don't need so much detail in your cloth, unless you are making a very old and wrinkled shark  

 

[Syrena]

On 25/04/2021 at 1:53 PM, skomdra said:

Did you try to make remesh with a bigger value and then test your struts how do they behave? You can always use that low poly sim to drive your high poly model with point deform, do you know how to set this up? It is rather simple. For such a simple movement you don't need so much detail in your cloth, unless you are making a very old and wrinkled shark  

 

Hello Drasko! You know Igor Zanic by the way?  He helped me before with some underwater stuffs in Houdini. Anyway, I know how to do that in Maya using NCLOTH (low poly sim drying a high poly...) but not in Houdini? Do you have a setup / example file for this please? I don't know... doesn't make sense. I use the Seahorse primitive and it works fine... but this shark doesn't work at all.

 

[skomdra]

On 5/4/2021 at 3:36 PM, Syrena said:

Hello Drasko! You know Igor Zanic by the way?  He helped me before with some underwater stuffs in Houdini. Anyway, I know how to do that in Maya using NCLOTH (low poly sim drying a high poly...) but not in Houdini? Do you have a setup / example file for this please? I don't know... doesn't make sense. I use the Seahorse primitive and it works fine... but this shark doesn't work at all.

 

Hi, no, I don't know Igor Zanic, the rabelway guy? He is from Serbia, I guess, our countries are not so close, unfortunately, especially now during the COVID, I wish I know him  did you try with a soft pin? Can you upload a hip file?