2/28 Video Mocap

This research seems cool, but like an awful lot of work. Obviously it's less work (and looks better) than key framing the whole animation, but there were just so many steps to it! Way more than the other research we've looked at, I think. I definitely don't think it's the best thing for all mocap situations, though it would be useful in situations where regular mocap is impossible. Things that are outside or need large, specific environments, for example. I was thinking maybe swimming. I only have a vague understanding of how regular mocap works, but I don't think it could really work to capture swimming, and obviously someone pretending to swim won't look right. If you had footage of someone swimming, this method might work. Also someone brought up mocapping specific people, such as athletes for their video games. I think this would definitely be a good option for that, since you don't need to bring in the person to physically act for you. Overall I think this method is interesting and useful for some specific situations, but for the most part I think standard mocap is probably better. Of course, I don't know exactly what goes into mocap, such as how you clean the data, etc.

2/23 Human Motion Synthesis with Optimization Based Graphs

I thought the idea of blending between motions or actions was really interesting. If it works well, it could really make things easier for an animator; just tell the character, do this, then this, then this, and not have to worry about what's going on in between. I feel like I say this a lot in these blogs, but this would be really great for video games. Since the character in the game can really do anything at any moment, depending on what the player chooses to do, there has to be transitions between actions. A lot of the time, this is 'easy' since the characters are walking - I feel like the animators can, for the most part, assume the action will come from either walking or standing, something neutral. For a lot of games, this will always be the case. This would be really good, though, for fighting games, so the character doesn't have to come back to neutral between each punch, kick, etc. Unfortunately I'm not sure if I completely understood how this method blends between actions... I got a bit lost in some of the math.

2/16 Perceptional Animation of Body and Hand Motions

Sophie Joerg gave a guest lecture today on her research regarding hand and finger animation. I guess I didn't realize how much finger motions can convey. Hands are obvious - we all talk with our hands, some more than others, because they help get our point across. When you talk with your hands, though, you don't (or at least I don't) think about what your fingers are doing; they just go, whereas you're consciously moving your hands. I think it's because of that that we can so easily notice strange finger motions. We don't think about them because they come so naturally, so when they look wrong it is very obvious.

I was also interested in what Sophie had to say about the idea of the uncanny valley. I've heard of it before, but no one has ever mentioned how it differs from person to person. For example, she showed a clip from The Polar Express and said how strange the characters looked and how bad the critics' reviews were, but honestly I didn't think the characters looked that unnatural. She said that to some people, the characters were creepy but some people didn't mind them at all - I definitely fell into the latter group. I didn't realize how greatly this affects different people.

2/14 Optimal Gait and Form for Animal Locomotion

This class we looked more at using optimization functions to control character motion. I thought it was pretty cool that the functions worked decently for all different sorts of characters: one legged, two legged, four legged with dog proportions, four legged with giraffe proportions, even five legged. Things like this are really useful - one method and one function that works for any sort of character. What I don't like is that it seems like so much trial and error. Randomly changing weights in the objective function until it "looks" right... I don't know of a better way to do it, but I wish there was one. It's like there's so much thought put into the different terms in the objective function, but the weights are completely arbitrary.

2/9 Sampling-based Contact-rich Motion Control

This lecture made me realize something. Derek made a comment about how he thought the character lifted his leg too high when he was sitting in the chair, relaxing, and crossing his legs. I didn't really think it was unnatural though. This made me realize that, so far, we haven't seen anything that takes into account flexibility. How does motion differ between, say, a ballerina, and a regular guy? I'm not saying high kicks or something - that different is obvious - but just basic actions. Like crossing your legs, for example. I'd be willing to bet a dancer would lift her leg higher than most people, because it really doesn't take that much effort when you're flexible. In fact, it feels natural. I think this might be interesting to explore for my project, though I'm not sure how I could create a concrete project out of this. I do think it's interesting that none of the research we have seen has explored this, though.

2/7 SIMBICON

We already talked in class about how awkward characters look when they move with a rigid spine. People simply don't move that way. Another thing I noticed, though, about the simulations is that they all landed on flat feet. This looks silly too, like the characters are constantly stomping around. We've seen other research where they give characters soft feet that bend a little on impact. Of course, something that detailed might not be necessary for this sort of simulation. What I was thinking is that there should be more effort put in to making the character lead with its heel, rather than the entire foot. When we walk, we put our heels down first and the rest of the foot follows, but it seems like the simulations are "aiming" their steps with the middle of the foot, making it land as a whole. Naturally, we walk heels first, but we can lead with our toes instead if we want to. Try walking by landing with your arch first. It doesn't work. If the simulations lead with their heels and allow the rest of the foot to follow in the step, I think the motion can look much more realistic.

2/2 Interactive Character Animation

What I found really interesting in this lecture was the research that used multiple objective functions to create the character animation. For example, the one where the person had to reach for the ball while still keeping himself balanced. I think this technique can be really useful. Yes, you want the character to perform a certain action, but you also want him to be physically plausible, and this is a good way to do it. Weighting physical constraints higher in your function than the desired action is an interesting way to maintain a character's believability. While we might not realize this, I think this is pretty similar to the way people think when we do certain actions. For example, imagine you're standing on a ledge and you want to get down. Reaching the ground is the action we want to perform, but that's not the only thing in our internal objective function. We also take into consideration our physical capabilities as well as our own safety. If the ledge is only a couple feet off the ground, we might just jump, but if the ledge is a lot higher, we think of another way to get down safely. We might sit down on the ledge and then jump, or look along the sides for some stairs. Sure, we don't think about complicated physics when we're deciding how to act, but we do take many things into consideration.