Hello

I know the plugion is for maya, but can you tell me if the plugin LipService w/lbrush from joealter do something that Houdini CAN'T do ?

It says it's comaprable to what mudbox or zbrush can do but on vidéos, the samples are animated…and zbrush/mudbox can't animate

http://www.lbrush.com/ [lbrush.com]

Thanks

Pose Space Deformation on a higher resolution mesh a la z-brush or mudbox. Sure.

Do a google search for Pose Space Deformation and you will see that there are quite a few resources out there. This should put Joe's tech in a friendly light.
http://imagine.inrialpes.fr/people/Francois.Faure/htmlCourses/PoseSpaceDeformation.html [imagine.inrialpes.fr]

Weta have documented the use of Pose Space Deformation (in Mari?). Weta have a wonderful resource in all the physical sculptors they employ and giving them sculpting tools to do PSD just makes sense as they are so fast and that is one of the special things that Weta does above everyone else and makes them amazing and unique. Everyone else? Dunno… Is there the budget to support this? Arguably for every shot with animated characters?

http://www.stuff.co.nz/technology/digital-living/8286490/Weta-honoured-at-Sci-Tech-Oscars [stuff.co.nz]

I don't know about R&H, Dreamworks or other vfx studios but I'd argue they have a set-up to do PSD as well to work out of some tricky character deformations.

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Houdini has an implementaion of Pose Space Deformation (PSD).

The way Pose Space Deformation works is after the base skin is run through the skinning Deform SOP, you then apply point deltas to the geometry after the deformed skin and these deltas are added to the geometry coming in to fix errors in the deformed mesh, not so much to add net new detail. Houdini does have this at the base level mesh.

One could argue that you could use a Subdivision SOP and bump up the geometry density and use the Edit SOP to sculpt in more detail as required or to fix problem animation results out of the skinning with the Deform SOP. Then you could bake out a sequence of displacement maps to do the deforms on the base skin as displacements.

What about sculpting vdb grid representation of your characters to bake the displacement maps?

There are a whole host of issues with Pose Space Deformation and in general the skin topology itself has to be nailed down or you have to work with uv's or attribute transfer attributes over to rescue the Pose Space Deformation attributes. All possible in Houdini btw.

So the toplogy should be locked down, animation pretty much approved then go to town with PSD and make sure you don't go over budget or over time.

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Having said all of this, the idea is NOT to do PSD, or to do it procedurally. It can send animation budgets through the roof if not contained. Houdini's muscle systems can do a decent job with shoulders built on top of decent armatures/bones. Houdini's muscles support workable inflation methods, self-intersection resolution (where the arm is animated in tight at the elbow), paintable surface sliding, baked in wrinkling and more.

If you create a nice elaborate shoulder rig with sliding clavicle's and somewhat anatomically correct joints along with plausible muscles, the results around the shoulder are very convincing. Without having to resort to PSD where it has to be managed in order to contain costs and time budgets. Who has enough scuplters around to maintain this in serious production crunches? How many animators can sculpt at a very high level? What if characters have to be re-animated based on late directoral changes? Happens more frequently than we would like. PSD is definitely an important tool for hero characters having said that.

Other areas where procedural PSD is used is to add some subtle skin deformations such as procedural lag or procedural wrinkling to add extra goodness to fur riding on the skin or for higher detail. The nice thing about procedural PSD is that it is very contained and doesn't rely on all out simulations or hand tweaking. That along with localized Smooth SOPs and Filter CHOPs on deformed character geometry (de-spike works very well).


Just my two cents worth. Arguments and disagreements always welcomed.

Will add in there: Reason why houdini inherently can support all these new techs? Is because it provides all the low level pieces to make them happen I remember before I knew Houdini, doing things such as PSD (or many other different specialized methods for mesh manipulation) I would have to write a plug in or get a plug in from the web. If the plug in did not fit the mold that I needed, well, good luck.

Since I have been using houdini, it is very easy to repro a lot of this functionality with general sops and vops. Heck, if you come up with your own deformation algorithm that is better than linear or dual quats, make it in vops

But I am with Jeff, I personally believe muscle sims is the way to go. Even if your output has to be PSD, do your high level rigging and deformation in muscles, then derive a PSD (or any other kind of solution) from the muscle sim source. To me this is ultimately the most scalable method

FWIW, there's the BlendPose CHOP in Houdini which will do the radial basis function interpolation that the original PSD paper calls for.