CGNetworks Product Focus
MuscleTK and The Making of Leon
Ali Tezel, 21 December 2004

Fresh on the trail of the newest innovations to 3D production, Ali Tezel (AKA SheepFactory) interviews CGToolkit to learn more about the creation of 3D creatures, its training DVD – The Making of Leon – and its Maya plugin used for Leon's muscle simulation.

Can you tell us about how this project came to life?

	The Making of Leon

The Making of Leon was created to give artists a sort of birds-eye-view of the entire high-end creature creation process. With The Making of Leon, we wanted the user to be exposed to every step along the way. That's why we left nothing to the imagination. You see Leon go from being a blob of clay on a workbench, to being a finished, displacement mapped and fully articulated animation puppet in Maya 6.0.

Once we recognized that this is what people wanted, it was simply a matter of finding and bringing the talent together to make it happen.

How similar is Muscle TK to the open source fusiform muscle plugin developed by Paul Thuriot and Eric Miller?

The idea is exactly the same with one major difference. Paul Thuriot and Eric Miller's plug-in will act on a muscle surface by affecting the transformations of that surface. It squashes and stretches a sphere's surface by simply affecting the translation, rotation and scale of that surface. Our fusiform muscle model is a deformer-based effect, capable of deforming any arbitrary surface geometry (NURBS only).

Thuriot and Miller definitely gave us the ideas; we just took them a step further.

Can you tell us a bit about the plugin and how it works?

MuscleTK was developed with Maya's API to provide an alternative to traditional smooth-skinning techniques. Rather than using a purely joint-based paradigm, setup artists using MuscleTK build their creature's underlying musculature. These NURBs surfaces are setup and attached to Maya joints to automatically flex and bulge. When applied to the skin surface via the muscleSkin deformer, the muscles will affect the final skin deformations.

How fast is Muscle TK and do you need to build your rig to specific guidelines for it to work?

A full body muscle rig can play back in real-time on a decent machine. The muscle deformers are pretty fast. The task of skinning with MuscleTK, however, is far slower than regular smooth skinning. You will not be able to scrub a muscleSkin bound rig in realtime.

For this reason, MuscleTK must be used in a pipeline that supports animation transfer. This is not uncommon. The animators do their work on a low resolution rig with absolutely no skinning whatsoever. When done, a TD copies the animation onto a high resolution rig (the one with all the muscles) and this is simulated for rendering.

To answer your question, the animation rig can be built however you want when using MuscleTK, but in order to transfer the animation, the joint layout must be the same.

The plugin has been updated since its launch not so long ago. Can you tell us about the new features?

We hope to update MuscleTK often. With each release, we will be listening to the user feedback and determining the direction of future development. We recently released v1.1 with a new feature called an action line.

Action Lines are a new way of controlling NURBS muscles. They allow for multi-belly type muscle surfaces with much more control. Action Lines video (29.1MB zip)

Can you simulate skin sliding over muscles?

Yes. The muscleSkin deformer has a paintable attribute that allows you to define, per vertex, the amount of influence that the muscles have. If you want the skin in a certain area to slide over the muscles, paint the influence into a shade of gray using Maya's artisan interface.

Can you localize the muscle deformation? For example if you only want it to affect certain vertices to speed up calculations.

Unfortunately no. This is a current limitation of the muscleSkin deformer based skinning method. We are currently working on a new skinning method that will hopefully allow for more control this way, but I can't say anything more about that yet.

What kind of support is offered to customers? Are the point upgrades free or is there a maintenance fee?

Everything is free to registered MuscleTK customers. You get free one year upgrades (if/when we come out with a new version, you get it), free email support and free access to our video training series that will help new users get to know MuscleTK and it's new features as they come out.

Do you support all operating systems that run Maya?

At the moment, Windows NT/XP and Linux are supported. After several user requests, we have also decided to make a MacOS version as well. Hopefully it will be ready in January 2005.

Who are the people involved in The Making of Leon ?

The Making of Leon involved a ton of talented individuals. Traditional clay sculpter Casey Love sculpted Leon, and the laser scanning was done by a marvelous company in Australia by name of headus, whose work can be seen in many feature films. The engineering and R&D was carried out by Zhang Jian. The rigging/narration was done by a Canadian artist by the name of Kiaran Ritchie. The entire team was organized and directed by Karim Biri, the owner of CGToolkit. It was quite an international team of talent! Mid-production, CGToolkit moved into San Rafael California , where it now operates.

Will there be more training DVDs made by you guys in the future or will you be focusing on updating the plugin from now on?

Our main focus is on software, so MuscleTK will obviously be getting a lot of our attention. We have a few ideas for new plugins and training materials as well. Look out for CGToolkit's first book coming out sometime in 2005. Also, we haven't ruled out the idea of another DVD set. I can't get more specific than that.

Related Links
CGToolkit
MuscleTK
The Making of Leon