Dr. Mark Snoswell is best known in the 3D industry as the creator of Absolute Character Tools - the world's first commercially available set of real time muscle and skin deformation tools. Mark hails from Adelaide, Australia but spends over half of his time in LA attached to various film productions requiring his character animation tools and rigging expertise. He is currently in Los Angeles consulting with Disney Feature Animation on a 3D animated film. I recently got to catch up with Mark on what he's up to and the current state of Absolute Character Tools.
Leonard Teo: Tell us about Snoswell Design, what are you guys working on at the moment?
Mark Snoswell: We have programmers in Madrid and Australia, I spend over half my time in LA. The studio in Adelaide is expanding rapidly with 5 people working on Disney and other A list feature film projects. We concentrate on high-end character rigging and skinning for film at present. This work primarily utilizes ACT and other software we have developed but has not been released commercially yet.
As for software development - in addition to ACT we have just about finished the Shave and Haircut port to Max, we have an advanced skinning system in use for film clients, there’s a way cool morph retargeting tool, and one of our programmers Gonzalo Rueda also worked on Kaydara’s HumanIK for Max with Di-O-Matic recently, so you can see that we have been very, very busy indeed. We plan to release most of the in-house software as commercial products in due course – the nice thing here is that the software will have been trailed in real production, before it goes out commercially.
Leonard Teo: What is Absolute Character Tools and why do people need it?
Mark Snoswell: ACT is a suite of software for creating muscles, skins and doing sub surface skin deformation. I want to emphasize here that it’s a whole new technology platform and a comprehensive suite of tools – it’s not “just a plugin” - and it’s production ready.
There are two major parts to ACT: New Primitives – cgMuscle & cgTube; and an extensive sub-skin deformation technology.
You don’t have to use these parts together. You can do sub skin deformation with spheres and meshes. Conversely you can render animations of muscles and build all manner of characters and objects with cgTubes without doing any sub surface deformation.
In future we will be adding more parts to the ACT suite of technology – things like whole new skin simulation systems that run faster than current skin systems but have almost no set up time, and default sets of skeleton, muscles and skins for humanoid characters.
The cgMuscles and cgTubes are a complete new class of 3D primitive. They do not derive from any other class of 3D object. They are resolution independent parametric surfaces – like NURBS, except they are about 130 times faster than a subdivided editable mesh and more than several thousand times faster than NURBS surfaces. The cgMuscles have the option of real time static forces (like gravity), collision and dynamics. The cgTube’s can be used to create character skins (proxy and sub skins) that deform in very realistic ways in real time.
The sub surface deformation is via the cgMeshDeformer. It includes not just sub surface deformation but also in-surface deformation which allows you to control surface stretching either manually or automatically.
Leonard Teo: Where did the development of ACT spawn from?
Mark Snoswell: ACT comes out of our focus on high end character animation and our desire to do it better than anyone has before. In the first version of ACT we addressed the biggest missing components of cg character animation – that is sub surface deformation by muscles and bones (you make bones from non-deforming cgMuscles).
Before ACT there were only relatively poor proprietary muscles and sub surface deformation software. It turns out that ACT performs better than these proprietary packages and it’s commercially available to everyone.
ACT 1.5 starts to address the creation of real-time, high quality, skinning with cgTubes. Although this is really just for creating proxy and sub skin character for now, it’s really a precursor for our whole new skinning system.
Next we will add a revolutionary new skin simulation system to ACT – we use it in house now, but we want to make it more generalized and idiot proof to set up and use before releasing as part of ACT.
The focus is always on high-end character animation – doing it better and more easily.
Leonard Teo: Do you think that ACT will revolutionize realistic character animation?
Mark Snoswell: ACT is already revolutionizing realistic character animation – I just can't talk about the film projects we are doing just now! Other than to say that our customers include the likes of Disney Feature Animation and Jim Henson Productions.
Image: This simulation of a human arm runs in real-time on a modest workstation (1.3GHz Athlon, Quadro DCC) and is anatomically accurate.
But seriously, yes, ACT is and will continue to revolutionize realistic character animation. I have been into the production houses and no-one has seen anything like ACT. I guess we got a bit lucky with the timing, but ACT is generations ahead of anything anyone is doing out there. We have also really pushed the speed of ACT – it’s very fast. So fast that we could do dozens of characters in real time on any of the leading games platforms. If we just had the programming resources to do the games engine port (hint, hint).
Something else that I want to stress – ACT is new. It’s been great to have so many opportunities to use it in feature film work. It’s a blast. People come to us with the best projects – they want to use ACT and they want us to set up the characters. It’s really great and pays for us to really push the software to the limit.
We have learned so many ways of using our own software – I have been really surprised by just how much you can do. One big surprise was just how fast it is to model characters with ACT – we never planned that. It turns out that all the structures we built into the muscles are perfect for modeling characters. This is one of the main reasons that we added the cgTubes in ACT 1.5. Now we find that modeling all sorts of things is faster (much, much faster) in ACT. Clothing for instance – creating realistic clothing with wrinkles is a snap with ACT because of the ability to soft select vertices in just the cross section or longitudinal directions.
I know no one has seen our in-house cgSkin system yet – but it’s working really, really well. Here we’ve already had some unexpected uses that we never designed for. To give an example – cgSkin can be driven by any “bone” object – even if it’s an animated and deforming mesh. We’ve found that “attached” things like beards, eyebrows, pockets, belts and the like can be almost perfectly driven by their underlying deforming meshes. It also opens up whole new ways to construct and animate things like deeply wrinkled skin and stretched membranes (like eyelids and bat wings). I should stop teasing people by talking about in house tools – we will add cgSkin to ACT as soon as we can – probably the next major release!
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Leonard Teo: In terms of ease-of-use, does ACT require a knowledge of human anatomy in order to produce good results?
Mark Snoswell: No. You can add just one general bulge under the skin to make it look like the skin is sliding over a muscle or bone – just adding one adds a tremendous degree of realism. It doesn’t have to correct at all. This is another surprise we have found. As soon as the eye can see the skin sliding over something underneath it seems to come to life. There is an impression that there is substance to the character. The “stuff” underneath makes it real and not just a deformed cg shell.
I can’t stress this enough – just having stuff under the skin makes your characters look so real. It doesn’t seem to matter so much that what’s under the skin is “anatomically” correct or not. The important thing is just to have something under the skin.
That’s not to say that you can do a much better job if you know some anatomy – to be honest, knowing anatomy makes the biggest difference in the way you rig and animate a character. I think this (rigging and animation) is far more important to making a character realistic. You can put “anatomical” muscles under the skin and do a bad animation and what you get is a “real” character that moves like a “cg” character. It looks alive – but deformed and badly animated.
Having said all that everyone is asking us for a pre-built set of anatomy for the human – and we are pushing to have that ready for release real soon now. To start with it will just be a reference set of muscles and bones – then we will turn it into a parametric system later (as soon as we can with limited resources). At that stage it will look like a cross between Poser and Hollow Man I suppose – kind of scary!
Leonard Teo: In terms of features, where is ACT at right now?
Mark Snoswell: ACT is the tip of the iceberg. We are about to add skin simulation in the next release and there are also major improvements we can make to both the performance and features of the core. Between ACT 1.0 and 1.5 the sub skin deformation sped up dramatically – over 1000 fold in some parts. But that’s all just features and specs – the really cool thing about ACT right now is that you can easily bring characters to life. Much more realistic life than anything you have seen in films or on TV to date, and it’s in reach of everyone. It’s exciting that a single person with ACT and 3ds max can significantly rival the quality of character animation that any of the giant production houses have been able to do. It’s way cool.
There are ways we could significantly improve the overall quality of cloth simulation when used in conjunction with ACT by generating iso-surfaces from ACT objects (muscles and skins). There are also a ton of other interactions that we could accelerate in practical terms – interactions with particle systems like water for instance.
We are also looking at creating custom deformers for solving difficult character animation problems for film productions. Although this work is in-house it’s made possible but the plug-in architecture designed into ACT – this makes it very easy for us, or anyone else, to extend ACT. [CGN|3DF]
Absolute Character Tools version 1.5 for 3ds max is immediately available from the ACT website. A Maya port is in the works.