Worms

[Blacko0ps]

Hi Guys

I am trying to make bunch of crawling earthworms using FEM in Houdini. This is my references : https://vimeo.com/53813166

I really need have control on path of each worm. My question is that how should I add path deformation to the simulation. I have tried to add it before tetrahedralizate node, but it affects on the geometry points.

Thanks

[Atom]

Have you seen Sam's work on earthworm locomotion?

[Blacko0ps]

Thanks for reply!  Yes, but in his setup the worm moves on a straight path. I wanna have a curvish path for each worm that I can have control over it. Like the reference that I have posted

Edited January 14, 2017 by Blacko0ps

[Atom]

Here is a simple example of deforming along a curve. I did not make the deforming scene, I found it floating around the forum. I exported the earthworm from Sam's scene and brought it into this deform along path example.

You'll need to come up with a way to create more curves and copies.

ap_path_deformer_worm.hipnc

[Blacko0ps]

Thanks man, but if I add organic tissue to example it will lose its animation. Sorry if I didn't explain it clearly. My question is that how can I convert your example to FEM and still have it moving along the path.

[Atom]

I don't think FEM supports deforming input geometry at this time of Houdini 15.5. I assumed you might simply simulate a single worm moving in a straight line then deform that pseudo organic animated sequence after the simulation is complete.

Here is another attempt at deforming the worm after the fact. Using a FOREACH loop for each curve produced by Matt's wire solver you can get a number of worms moving along randomly over top one another. Increase the curve count to add more worms.

ap_me_wire_worms_along_path.hipnc

Edited January 14, 2017 by Atom

[Blacko0ps]

Thank you so much man! I think this somehow could work.

[mattvfx]

you can use a target mesh to influence your FEM simulation or a animated rest mesh .   

 

http://ihoudini.blogspot.com/2013/12/worm-locomotion-with-fem.html

 

 

[Blacko0ps]

Hi Matt,  not sure about target mesh, is it same as Point deform node?  I have tried adding rest position to my animated mesh, but when I transfer it to FEM simulation it lose the animation. 

[mattvfx]

you can import the target mesh or the rest mesh in the solid object dop node . then you have to use the targetStiffness targetDamping or pintoanimation per point attributes .

in the finite elements master class from sesi you can learn how to set-up the target mesh. 

 

 

Edited January 15, 2017 by mattvfx

[Blacko0ps]

Thanks Matt! it seems works for different kind of deformation, but not path deformation. I think I'll use the wire solver method that Atom mentioned above, at least gives me closer result. 

Edited January 18, 2017 by Blacko0ps

[anthonymcgrath]

the worms setup with the wire solver is luuuuurrrrvely!  It might be worth using that to get your initial deformation - then pass that little lot through a fem solver to get some gravity and nice intercollision between them!

target geometry is fairly easy to do overall - i used it to get these squidgy things to move under animator control by simply animating a translating/rotating version of the geometry and using that as target.  The same for the rest geo - but you need to ensure both of these things are using the same tetrahedralised result otherwise it just tends to bork out and go weird.  also when using rest/target you need to turn up the value in the solver too otherwise it wont do a great deal - theres a stiffness and damping for your target.

 

 

[Blacko0ps]

Hi Anthony,

Very nice work on your FEM animation!

I have been trying add FEM to the wire solver result, but again whenever I add the FEM it loses its animation. Still figuring out how to work with target geometry, but I couldn't get it to work. 

Also, my second question is that, I have bunch of seeds that I want them to have interaction with my worms. Something like worms are crashing and eating the seeds.  Do you think would be the best approach for that?

I have attached my file here 

Worm_10.hipnc

Edited January 22, 2017 by Blacko0ps