January 3rd, 2013 at 5:00pm PST, Agenda and Minutes
The teleconference convened at 2000 and adjourned at 2230 hrs Eastern Time Zone
Attendees: Myeong Won Lee, William Glascoe, Joe Williams, and Dick Puk
Myeong discussed her group's content creation process (skelton and skin together) displace binding; deformers (not displacers)
Joe described the H-Anim specification nodes: skin coord index and skin coord weight (a lot of vertices in the skin but all are bound to joint we use displacer for moving skin independent of joint motion. For example, to raise an eye brow, you send commands to displacer node to move the eye brow representing motion of the skin while the skelton remains still.
Take a LOA3 skelton as an example. It has...joints. When shoulder joint rotates the entire arm moves. If I move the wrist, all the hand joint move too. It's done in a hierarchy like this to achieve realistic measurements.
Joe explained the text file of the running man he sent to us a few weeks ago. The skin animation (the running human) the visible bones is the geometry part of the skelton. There are two things that move a skin-
1) joint translation 2) joint rotation
Myeong and Joe discussed skin nodes. Joe summarized the skins he has seen in projects. Many were not built in skelton space. They were built in "skin space". Sandy Ressler's skin is 40 times larger than a normal adult human. His character has 30,000 vertices, which is too many to connect with conventional authoring tools. The only practical way to use ii is to bind to the joints. One must bind textured geometry to the segments. But we want a realistic moving skin. In the skin node, ...face set... Most of these are called "skull tip". That other skelton is approximate 1.77 meters tall. I think it's important to build a skin in skelton space to avoid a lot of transformations. If my skin points correspond to my feature points, then I have a realistic character. You see that everyone of these is a named feature point (see the H-Anim Spec Annex B). There is not enough detail to do a lot of things in Joe's example but he did add a few feature points for more realism.
Joe explained how some of the Motion Capture (MoCap) systems and projects don't worry about the skin. They create the skelton and put any skin on it they want. He said a good example is what happened in the Lord of the Rings movie. The readouts had no skin. You can follow the points inferred from the skelton. They did capture skin motion initially but that's not the norm today.
Myeong assigned members to the ten work items.
- 1 Myeong and Joe
- 2 Myeong and William
- 3 Myeong and Joe
- 4 Myeong and Dick
- 5 Myeong and Dick
- 6 Myeong and Joe
- 7 Don and William
- 8 Joe
- 9 Don and William
- 0 Myeong and Joe