Review: IKinema for Maya
Developer IKinema brings a fresh face to full-body animation in Maya. 3D World asks if it’s a solver for all seasons
IKinema enables artists to jump straight into animating, bypassing traditional set-up methods
£320 / $495 / €360
- Real-time streaming of motion capture (XSens/Vicon) into Maya
- Full-body posing of character models
- Retargeting from any source to any target
- Apply forces (weight, momentum) to enhance existing animation
- Offline and runtime implementations
Developments in CG animation technology are rapid.
Startup developers frequently purport to be bringing to market the next groundbreaking suite of software that will create movie-quality motion at the press of a few buttons.
With such bold claims, it’s important to see if such assertions stand up in the real world.
Guildford-based IKinema is one such startup. Armed with tech reportedly distilled from research into spacecraft control, it’s developed a plug-in for Maya that boasts true full-body animation of any hierarchy, without the need to go through an intermediary rig or characterisation process (à la HumanIK).
Coupled with this, a straightforward retargeting interface and real-time streaming from popular mocap packages makes for an impressive résumé.
Not to leave game developers out in the cold, runtime implementations for consoles and the ability to add physics constraints to dynamically alter existing motion are also on offer.
Physics infl uences allow characters to react dynamically to real-world forces in a lifelike manner, both at runtime and offl ine
A quick set-up process first creates an instance of the solver at the root of your hierarchy.
Once populated, you can specify what IKinema calls tasks (essentially constraints), which drive a particular joint in position or orientation.
For a generic biped, this would amount to position tasks at the hips, hands, feet, shoulders and neck base, plus an orientation on the head.
The simple workflow is akin to setting up standard chain IK.
If desired, task nodes can be parented under primitive control objects of the kind one might find in a traditional rig.
Tasks are manipulated in the viewport, and the solver determines the most believable pose over the full-body rig while satisfying these tasks.
The end result is of course tunable: you have the ability to set limits restricting movement on a given axis, and sliding an additional mobility attribute has the effect of stiffening the joint up or allowing for more flexibility.
Tasks can also be assigned differing priorities: the solver will bias the posture to satisfy any tasks that you’ve awarded higher importance.
The benefits of this workflow are clear compared to traditional character set-up, which demands highly specialised skills to build complex rigs with myriad controls.
Being able to work on unconventional hierarchies is a major advantage too.
IKinema in use
Physics infl uences allow characters to react dynamically to real-world forces in a lifelike manner, both at runtime and offline
On loading the plug-in, you’re shown a dedicated menu and persistent tool shelf.
The icons aren’t immediately intuitive, with several looking similar to each other.
Even with repeated use, you may find you need the tooltips to jog your memory.
Since most artists will likely be interested in straight-up full-body animation, let’s use a simple biped with low spine resolution (two joints) as an example.
Set-up is completed in seconds with a few clicks; slightly longer if you go to the trouble of making control objects.
Once joint limits have been tuned via on-screen controls, the business of animating can begin.
Simple animations can be knocked out fairly rapidly, achieving fluid, believable motion with little effort.
Overall, the solver works well, and for those wanting to animate in FK you are given the option of duplicating the entire hierarchy (effectively setting up a 1:1 retarget) and using those joints to key FK rotations in addition to
This works, although it’s not as convenient as a true IK/FK switch in a good articulation rig.
With a more detailed skeleton, additional care is needed in setting up and tuning, and the solver is prone to less predictable behaviour.
Selecting undo will not always guarantee a return to the exact space you had before moving your task, which can be quite frustrating.
The solver model is currently non-deterministic, such that playing from frame 0 can give a slightly different result each time.
Future development could perhaps address this with an additional solving mode.
If you have existing animation to re-target, this can be achieved through a basic interface for mapping source to target.
While it will do its best to match bones based on namespace, it’s fairly straightforward to script an automation with the supplied API.
This also becomes necessary when working with a large data set, as there is no batch mode.
Mapped tasks can have scale attributes tweaked to compensate for size discrepancies between characters, although it’s generally worth globally scaling skeletons first to have the best shot at eliminating footskate:
relying on the attributes alone doesn’t entirely solve the issue.
Mocap users get to stream data in real time directly to Maya, which is good news for practitioners of virtual production methods.
Frame rates are acceptable, even for scenes on the heavy side – more so with Maya 2011’s Viewport 2.0. Rendering may not be as speedy as a dedicated real-time engine, but that’s weighed against the luxury of keeping everything in a single package.
Recording functionality comes in the box, although without the presence of native ‘takes’ in Maya, there can be some clumsy fiddling with animation layers to capture multiple performances.
Joints can have force attributes added to describe physical properties, and the results are impressive.
Combined with a movable centre of mass, characters can react to uneven surfaces, weighty objects and the like in a lifelike way, using arms to balance and truly involving the whole body.
While this looks cool playing around in an offline scene, game developers would benefit most here, where force tasks can be driven by a traditional physics pipeline to dynamically change motion in-game.
With an attractive price point compared to rival animation-specific packages,
there’s great potential here for the artist or small studio looking to animate in a hurry, allowing time to be invested more on crafting motion and less on initial set-up.
For high-end productions and studios with bigger budgets, however, character teams would almost certainly still want to go to the trouble of creating a full articulation rig from scratch to allow precise and predictable control.
The solver can be applied to unconventional hierarchies, enabling you to animate a variety of characters
IKinema remains of great value in this arena, though: model teams can quickly pose test topology; character TDs can prototype deformer systems and joint placements; and mocap teams can take data into Maya earlier in the process, for either live retargeting or post editing.
It’s in this latter area that it seems the most value is to be had in IKinema’s current incarnation.
IKinema is a quality release that will benefit animators at any level, whether utilising the straight-up full-body tools or streamlining existing pipelines
• Retargeting and streaming directly in Maya
• Solving model works well on a variety of non-standard hierarchies
• Speedy set-up and intuitive workflows
• Solver can be unpredictable with very detailed skeletons
• No batch retargeting out of the box
• Noticeable absence of floor contacts when performing detailed edits
on Saturday, June 25th, 2011 at 3:00 pm under Plug-ins, Reviews.
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Tags: ikinema, Maya, plug-in, review