More playing around; altered the speed of the first drop, changing around some of the timings on the successive bounces and also tweaking the rotation during the rise and fall of each bounce.
It's still not looking right to me - I think now that it drops too suddenly on the second bounce, so I need to slightly adjust that one. Widening the top of the curve should sort it.
I'm actually wondering at this point whether it doesn't bounce quite high enough on the third bounce - it's obviously losing energy, but having such a short hop doesn't give much room for acceleration. I'm thinking that maybe we don't get a feel for its weight because there's not enough time/space between each keyframe to show the difference in speed as it climbs and drops again? Or something?
Started cleaning up the rotoscope; first I lengthened and slowed down the shot, which massively improved things. I think it's looking a bit better now; the main things I had to alter were, as said previously, the speed of the ball's drops and the hangtime at the peak of the bounce. I messed around with the rotation slightly as it's falling, and also reduced the distance that the ball rolls away.
I'm not terribly happy with the rolling at the end - it looks off to me, but I can't seem to put my finger on exactly what's wrong. I feel as if maybe it starts rolling too soon after landing - I can't explain it, but it looks as if the ball is sliding more than anything. Perhaps the rotation doesn't quite match up to the speed of the movement? Maybe it's the timing on the movement?
The initial drop seems a bit too slow as well - the ball lacks any real weight and I think some of the successive bounces need a bit of tweaking as well. They're a little choppy? Overall, I'm not too sure about any of it - the ball, to me, doesn't seem to carry any particular weight of character. Maybe it hangs in the air too long as well?
Taking a brief break from fcurves, thought I'd have a bit of fun playing around with Softimage's rotoscope options. You can basically attach an image to the back of any viewport to use as modelling reference. That in itself isn't especially useful for my purposes, but in addition to static images, Softimage allows you to attach image sequences as well.
I found a video on Youtube of a guy dropping a bowling ball in front of the camera and decided to try playing around with it.
Mucking around with trying to convert the file to an image sequence appears to have messed up the frame rate (it was probably originally shot at 29fps, come to think of it) so the final version appears to be on fast forward, but hey ho.
To attach the sequence, click on the display option dropdown in the top right of any viewport and click on 'Rotoscope' which will bring up the 'Rotoscopy' property page.
Clicking on New > New from file then opens up a dialogue box - by default, Softimage looks in the 'pictures' folder for all rotoscopy images. I used the terribly-converted bowling ball image sequence, which Softimage then pins to the back of the scene.
Scrubbing the timeline will play back the image sequence! Magical. The only problem is scale - as you can see, simply dropping in a primitive sphere reveals how tiny the image is, which isn't always ideal. In most cases you could simply scale down your object but in instances where you have a complex character rig, you don't really want to scale it down too much.
The other option is to enable the 'attached to camera' checkbox in the rotoscopy property page. This basically fixes the rotoscope to the lens of the camera so you're able to pan around with the camera and line up your object over the rotoscope without altering its position. You can zoom in and out of your object without effecting the scale of either the object or the rotoscope.
When you're happy with the positioning, you can turn on 'enable pixel zoom' (the square magnifying glass at the top of the viewport' which locks the position of the rotoscope and object together.
Sorry if that made no sense. I'm still very tired!
Anyway, I didn't get too fancy with it. I just wanted to see how it worked, mostly, so literally all I did was trace the position of the ball with keyframes - no fancy fcurve editing (yet)!
Wireframe:
No distracting background:
Of course direct rotoscoping never usually works - for things like ball bounces the results can be decent enough, but in the case of more organic or lively motion (particularly walk cycles) the resulting animation can lose a lot of the original personality and weight. Rotoscope and motion capture can be a great starting point for overall timing and to get a very basic animation down, but they usually require so much cleanup afterwards you may as well be animating from scratch!
Anyway, I actually think that the rotoscope looks mostly OK - there's certainly a feeling of some kind of weight, but there's a lot of tweaking and refining that could be done. I think the overall speed is probably a bit too fast, mostly due to the problems in converting the frame rate - so I'll probably sort that out with the region select tool in the dope sheet. Once the speed is sorted out it should be a little easier to pinpoint the exact problems with it, but I think generally the series of successive bounces could use some work. Looking at the original footage there is a noticeable pause at the peak of each bounce before it comes back down, which mine definitely lacks. This should be easy enough to fix.
As an aside, I also think that the ball rolls away a little too long at the end, but that could simply be due to the fact that the rest of the animation is too fast in comparison.
