Hey everybody,
I just bumped into this page:
http://www.kickstandlabs.com/tools/ [kickstandlabs.com]
they do a plug-in called stretch mesh for maya that looks really powerful for realistic deformation…

It reminds me partially of the soft contact deformer from http://www.aearon.de/ [aearon.de] but It seems to go further…

I was wondering if this could be done in Houdini, my guess is yes, but my brain is not able to do such things yet…

Anyone ever tryed to do something like that? What are your thought on the subject? (I want that in Houidini 10!)

Learn Python, and create the tool yourself! ;-)

It's a little hard to tell precisely the full range of the toolset(err, without sitting through the whole, slow streaming presentation that is… ), but certainly most of the molding and transforming I'm seeing there could be accomplished by using magnets and soft transform. Houdini is it's own beast, a soft transform is nothing more complicated than selecting some points, a falloff, and pulling.

I'm suspecting much of their value is in the interface to it, plus they may well have some clever algorithms that aren't immediately obvious, but you could give those two SOPs a go…

Cheers,

J.C.

I can't find the vid, but is it like stretch modifier in Max or maybe a custom verlet cloth deformer on a skin node?




Cheers.

Something I'd like to see in Houdini is some way of using Dops solvers in the modelling environment, this kind of thing could then be set up as a cloth or squishy object solver but that runs in the time space of the real world as you interact with the model (just as in the stretch mesh demo) rather than in the time space of the animation world. That would be very cool.

But as noted a lot of what is in that demo can be setup with magnets and soft transforms. The old ball under a cloth is a classic magnet demo, what would be more interesting to see is a teapot or bunny moving around under the cloth, that would be way more challenging to setup with magnets….

From what I see and understand, it's much much than just soft transform, but it's not quite dynamic neither. The way it deform is clearly superior to what you can get from a soft transform, because it tends to maintain volumes. Which is a SUPER important point for character deformation and animation, it makes thing so much more belivables.
It's what most of 3D apps miss yet with their deformations.

It reminds me of a paper from pixar:
http://graphics.pixar.com/library/HarmonicCoordinatesB/index.html [graphics.pixar.com]

It's about deformations using Harmonics coordinates, Stretch mesh might be using something similar(my guess).

Simon: You're right thought, objects in the demo are really simple. I totally agree, we'd need to see it in action with a more complexe object.

Its not harmonic coordinates its more like a cloth sim but setup as a rubber sheet.
Harmonic coordinates require a control mesh.

It doesn't look like it does any volume preservation, just look at the arm example with the sphere collider in the elbow, it just effects the local area. You could do that with a magnet btw.

In fact look at any of the examples neither the area or the volume are preserved as the surface is treated like rubber.

Simon:
interesting comment, so I guess I don't have to be too sad to not have this in my tool box….Alright, so I want real Harmonic deformations than!

You might also want to check out the Inflate SOP.

Hey Simon,

You comment tweaked me to send you this. I've been experimenting with sops to help students understand the nature of the data in dops and how it can be put to use. Showing this stuff in Singapore at the moment to good effect.
I think it very cool that you can pull any data from a dops network and play with it there. This examples is using the vel/Visualization data.

I've been using that data as well with particles, applying point forces to the vel/Visualization curves in sop to influence particles. Plus just directly generating particles from the visualized curves.

Lots of fun.

Simon
Something I'd like to see in Houdini is some way of using Dops solvers in the modelling environment, this kind of thing could then be set up as a cloth or squishy object solver but that runs in the time space of the real world as you interact with the model (just as in the stretch mesh demo) rather than in the time space of the animation world. That would be very cool.

But as noted a lot of what is in that demo can be setup with magnets and soft transforms. The old ball under a cloth is a classic magnet demo, what would be more interesting to see is a teapot or bunny moving around under the cloth, that would be way more challenging to setup with magnets….