Physical Props (Proposal Breakdpwn Part 2)

The second section of my proposal spoke of physical props although this will actually include all the things to think about when capturing the initial data. For example this quote from "Puppetology: Science or Cult?" by Brad deGraf and Emre Yilmaz in regards to the initial capture with non human characters in mind for the target link: http://www.awn.com/mag/issue3.11/3.11pages/degrafmotion.php3 "Ironically, it's often better to have less data than more -- we usually use only 12 body sensors. If you had one sensor for every single moving part of the body, you'd have a lot more information tying you to the human form, but for our purposes we just want enough sensors to convey the broad lines and arcs of the body."  Through my research I found a number of interesting contraptions that were used to modify human motion for use in motion capture.. They all looked a little dangerous though. This was used to help influence the movements of the Pleo the dinosaur toy: Pleo the Dinosaur for planet of the apes andy Serkis used stilt like extensions on his arms to help mimic apelike movement more effectively. Andy Serkis Giant Studios, which motion-captured live performers in choreographed fights to provide critical data for the animators of Reel Steel Reel Steel Groot in the Guardians of the Galaxy films due to be released this year is played by vin Diesel who has been sighted getting used to the props that will help him with the extra height needed when performing. Acting Techniques Using acting techniques to manipulate the data during capture is a useful tactic and much safer for me to investigate than some of the contraptions mentioned. Andy Serkis again is a great example of this in both his role as Caesar in planet of the apes and also as Gollem in the lord of the rings and hobbit films. Andy Serkis Disney did some research into this technique but instead of taking the straight capture they took key poses form the source data and matched it to the equivalent pose for the target character. From Research paper by Yamane (2010) link: http://www.disneyresearch.com/wp-content/uploads/nonhumanoid_sca10.pdf Moving Forward I think the main focus will be the acting techniques rather than the props other than maybe basic ones to help with weighting, for example if the character is meant to have more weight on the arms I could get the actor to hold something to imitate the extra weight.

Preserving Motion Through Retargetting (Proposal breakdown part 1)

This will be quite a long post outlining the work I did researching for the proposal. (I might split it into a few posts) I generally used my notebook to keep track of ideas rather than my blog which is why it has been a bit neglected however my notes are a little all over the place so I'll do my best to keep it from being confusing.

The main sections for my literature review were as follows:

• Preserving motion through retargeting
• Physical Props
• Acting and Key Poses
• Lattice deformations and Spline IK
• Spasm: Procedural Animation and real-time retargeting.

1. Preserving motion through retargeting.

Gleicher - developed a solver which preserved desirable qualities of motion using space time constraints to allow interactive control of animation via UI. The process described in the 1998 paper delivered as part of SIGGRAPH '98 initially uses the angles of the source characters joints to drive the movement in the target character however this leads to problems when the character is scaled as shown in figure 2 taken from the journal itself. 

To fix this he used IK solvers to help apply constraints to the characters feet, forcing them to stay planted but as IK solvers consider each frame independently it doesn't know what the motion is in relation to the frames around it resulting in "high frequency jerkiness".

Spacetime constraints: (Witkin and Kass 1988) uses 3 factors to help dictate the movement needed. What the character needs to do or the mechanical action of whats being moved so from one place to another or onto something etc, How it needs to do it so characteristics of the movements. and also how the physical structure of the character would affect the movement for example how the joints are able to move, what the mass of the character is etc.

Main problem Gleicher had was that despite being able to replicate the movements of the source character it took out all personality. 

Gleichers work may be beneficial in transplanting movements from source to target for replicating the mechanics of the movement but when retargeting to a target that has a different structure to the source then I would have thought a little flex from the original movement might be useful but then again with space time constraints one of the factors is the physical structure of the character which could either break the movement entirely or cope with it.. Might be a useful thing to look into?

Moving Forward
I mentioned in my dissertation about unity's mecanim and Mayas human IK, both these tools focus on the retargetting side of things specifically. I feel like exploring the possibilities these two processes offer would be in my best interest so I'll dedicate a post specifically to research into their capabilities hopefully resulting in pipelines specific to those.