Well... here goes my first try at exercise 1a bounce a ball

Ball one.mov is done with Animators survival kit's timing.....with my squash and stretch added to his timing

Ball three.mov is changing the timing and squash/stretch on the end bounces

thanks for your time

Steve

Hi Steve.
Welcome to the Bootcamp.

To your bouncing ball. It is a good start.
There are only a few things to change. When the ball hits the ground you need three keyframes. The first one should be the maximun streched ball that contacts the ground. Then you can squash your ball. The third one should be also a streched ball that has left the ground already. I have made the same faults, but robcat helped me a lot. Here is my bootcamp-threat.
Especially robcats second should help you much.
http://www.hash.com/forums/index.php?showtopic=21356

Another useful statement is this one.
c-wheeler:
"At the top of the arc, grab the bias handles and make a soft "D"curve to give it some "hang-time" where the ball is at zero squash/stretch, then at the bottom of the arc, where the motion is violently reversed, make sure the bias handles are close together and you have more of a "v" curve. If you do it like this on the motion bone in the Y axis, you only need to key at the top and bottom of the bounces"

A few edits and you will have a good bouncing ball.

Great start Steve. You followed pretty much all of the squash & stretch as in the Survival Book, but the timing you need to pay close attention to. The ball needs to interact with the gravity. It has to accelerate when going down and decelerate when reaching the high point. Right now the bounces seem to have constant velocity.

Daniel gives you the solution to tackle the problem.

Keep up the good work.

Thanks guys

now i've adjusted the bais handles on the ball movement and squash/stretch

and i've changed the drop of the ball ...speeding up the drop ( for gravity )

i hope this is more like it

Steve

Much, MUCH better

Now fine tune it, don't cut it short. Let the ball drop and bounce, naturally, to a standstill.

That looks mostly good and is very close.

a few notes:

-the first four bounces take 16 frames each and the last two take 11 frames each. why? Why does that look unnatural for a decaying bounce? Put another way... how can a ball falling from a low height (as on the fourth hop) take as long to reach the ground as one falling from a high height (as on the first hop)?

-To do it the Richard Williams way, the frame before the squash should be touching the ground. It helps to make the squash appear less of a pop.

-The distance between the squash and the next frame should be the biggest distance the ball covers on the way up. A ball can not gain upward speed after it leaves the ground

-troubling screen name

hehe so many things to think about ...ok i added a tiny finish bounce

thanks Dhar for your time

sm



i think i had to read your notes like 10 times lol....but i think i got it ( i hope lol )

i did 2 more ball bounces

only difference in seven is what you said in the last note ....next frame the biggest disance the ball covers and i think it's the finish touch

thanks alot robcat

sm

I think most observers would say that #7 is going too far in the one frame.

#6 still has the the old spacing problem as before.

really, the up and down progress of the ball mirror each other except for the fine points arounf the squash.

The up shouldn't be longer than the down and the down shouldn't be longer than the up in any one arc.

The decay of the bounces seems much better now.

There is a limit to this acceleration and its often interpreted in various ways.
For comic effect the acceleration can keep increasing in an exaggerated way BUT if the ball is falling without any force behind it there is only a very limited acceleration. As I understand it, the ball will accelerate to 32 feet per second and remain at that speed until something forces (!) a change.

In the first Bootcamp there is no force behind the drop of the ball so there should be little acceleration.
If the ball is thrown or fired from a cannon... obvious acceleration will occur.

Richard Williams's book completely omits the 'forceless' dropping of the ball and works with balls moving in arcs. Books such as Chris Webster's 'Animation - The mechanics of motion' cover it but not in much depth.
I suspect the reason for ommission is that force is almost always used to hint at object motivation in animation. The force behind the object (even when not seen) compels the object when it moves. Once an object is in motion it then can interact and become the force behind other objects (read: characters) motion.

'Animation - The mechanics of motion' does contain one example that I've used often in teaching marksmanship and it demonstrates the principle of falling objects pretty well in a fairly simple way.

It goes like this:
If a bullet were dropped from muzzle height of a rifle at the same instant a bullet is fired from the gun... which bullet hits the ground first? A: All things considered* they both impact at exactly the same time. Gravity is the constant that accounts for this phenomenon.

*Note that variables such as wind, elevation, bullet trajectory, slope of terrain etc. must be considered, eliminated and/or accounted for in such circumstances. It could really only be measured accurately in a vacuum.

So, what am I saying?
The ball in Bootcamp Exercise I need not accelerate on its way down if it has reached the speed of 32 feet per second. This is not to say that it can't accelerate but force is automatically implied if it does.

The good news is that once you finish with ABC exericse I you'll rarely see a straight ball drop in animation.
Understanding the basic principle behind a force-less fall will improve the look of falling objects in your animation.

Additionally, the stretch on the frame of impact (that Robert relates) is a trick to make the animation flow smoother and it works! Its not acceleration though. Its literally and figuatively a stretch.

Richard Williams places emphasis on spacing over squash and stretch.
In his words, "I've found that you can get a good enough effect with a rigid coin - provided the spacing of it was right - so this added techique is not always necessary."

Considering the the object is a factor here and I'm sure the reason Mr. Williams uses a penny in his demonstration.

Make sense?

Edit: I stand corrected by Robcat (See below). My comments not properly taking into effect gravity. The gun example is very true though and demonstrates that all objects fall at the same rate given the same time to fall.

Hold on there... someone's repealing the law of gravity!

That's 32 feet per second per second. Meaning that after one second the ball is falling at 32 feet/sec, but over the next second gravity will add another 32 feet/sec (total of 64 feet/sec) and in the next second it adds another 32 feet/sec ( now falling at 96 feet/sec) and so on.


And it will accelerate because gravity never gives up!

There is a point at which air resistance will become so great that it balances out gravity and the ball will not accelerate any more, but it takes quite a great speed to reach that.

In most everyday situations air resistance is exceedingly minor and for our "Bouncing Ball" exercise we ignore it entirely.

Robcat,
You are right and I am wrong.
I'm trying to imagine the maximum speed at which an object will fall with (normal) gravity and I left the factor of gravity out (as you state).

The acceleration of gravity is said to be: g = -9.81 m/s^2

Well drat... I'll leave what I wrote for everyone to look at and apologize for any confusion.

Anyone know what I'm talking about with regard to maximum speed of a falling object?
Maximum speed isn't the correct term.

Added: I found this site that has some example of basic object movement: Making Stuff Move

Lots of cool (and rather simple) examples to be found on the internet: Introduction to Freefall

ok so i started over ..because of the timing issues

so here goes...

Thanks for posting the graphs. THis helps us to really see why the ball is doing what it is doing

you're really close but...

Your ball is still slowing down as it approaches the ground and speeding up after it leave s the ground. But that can't be for a bouncing ball.

A falling ball can only fall farther and farther in each frame because it is pulled down by gravity.

A ball bouncing up can only travel less and less in each frame because it is pulled down by gravity.

By not peaking those CPs i've circled in blue, the graph is made to flatten out around the ground, which means the ball is traveling slower. peak those CPs and adjust the bias handles to make those graphs into parabolas.

thanks alot for your time Robcat

i had to look up what a "Parabola" looks like hehe

i hope this is what you meant ...

i wasn't sure where to place the stretch keyframes ( should they mirror each other on the valley? )

Steve

We're edging closer ...

we want the stretch before the squash to be touching the ground.

This is way, way easier if you peak (just like if you were peaking a spline in a model) the CPs onthe ground so you can make sharp changes in the curve.

The ground is not where things change slowly and smoothly. It is where things change suddenly.

like this
[attachmentid=16647]

There will be many many animation situations where you need to break that curve up and make something change suddenly

ok i didn't know you could peak the bias ( i discovered it on a right click lol )

very nice example it helped alot

so moving right along to the exercise of 2 balls ...

the right ball has no squach /stretch because i wanted to be hard and heavy

sm

Here's 2 balls bouncing across the ground

abc 1c

i add the curves for both balls




Steve

ok now for my bouncing Ball with tail trick ....

abc 1d

i added the curves for the 3 bones in the tail

base, middle and tip

Steve

Just me again

finished the ball with tail bouncing across the ground

ABC 1e

now the alive Balls bouncing along ( holding hands ..if they had hands or even arms hehe )

ABC 1f

i added the white and yellow balls curves

thanks

Steve

Lets go back to the two balls falling straight down.

You got a good fall for the ball on the left by editing that curve so the ball is alway accelerating on the way down... but not for the ball on the right? The right ball needs it too. All falling objects will need it.

I marked the center of the right ball with a green dot and we can see it's moving less and less as it approaches the ground. Its coming in for a soft landing. And if we look at the curve for the right ball we see that it is actually beginning to level out a bit before the impact; that means it is slowing down. Can't be. It should be getting steeper and steeper right into the ground. The curves on the subsequent bounces look suspect too.

Another note... for a rigid ball try just having one contact frame. We needed two on the other ball to accomodate squash and stretch, but probably not on a rigid ball that isn't squetching. Just make sure the bal isn't in exactly the same location onthe frame before and after the singel contact frame..

Now on to the left ball: the fall is falling well so it took me a moment to figure out why the bounce looked out of place. It's too much squash, but it's a little tricky to explain why

I tracked the trailing edge of the ball on the first fall. Its great right up thru the first contact frame.

on the next frame the leading edge of the ball obviously can't go any farther... it's against the ground. So far so good.

Squash happens because the trailing portion of the ball (this non-rigid ball) tries to keep going. It has momentum, it wants to keep moving, but as it goes down it's going to immediately encounter the rest of the ball being squished underneath it and getting compressed and pushing back. Unless the ball were made of some completely flimsy material the trailing edge wouldn't be able to squash that far down, and if it were I don't think it would ever be able to pop back up.

Right now the ball is squashing down faster than it was falling; probably not possible. I'd cut the squash down by about half, or may be use less stretch leading into the squash.

thanks Robcat for your time ,

yes i exaggerated the squash and stretch for the left ball ( good eye )

i dropped the 2 contact points for the right ball and fixed the drop speed

hmm i think i'm catching on ......hehe

thanks again

Steve


forgot my mov. file

ABC 1G alive ball bouncing along ( and a screach to a stop )

i included 4 curves ....



Steve

now i found a lamp model ( off Cristin McKee Animate Cd's )

i just added a light and set the bulb ambiance to 100 percent

so here's my lamp hop cycle

ABC 1I



Steve

Now thanks to Cristin McKee Animate Cd's

i finished my Lamp jump

ABC 1 J Pixer lamp jump




Steve

ABC 1K/L Juice Box shuffle/ Hop


( not sure what a shuffle would look like so i did a combo of hop and jump )


enjoy

Steve

ABC 1 M a piece of seaweed in the tide (just make a chain of bones, and attach some primitives to each segment)

i included the models and project

thanks

Steve

ABC 1 N Whip

ok let the music begin ...whip it good


thanks

Steve

ABC 1 O the Pendulum

you are getting sleepy

and now you're awake and feeling refreshed

thanks


Steve

Hi Stinkyu111, I really like the bouncing ball thing, but I have a slight problem with the pendulum. I am by NO MEANS an expert on this stuff, but shouldn't that rotate from the top point on the pendulum?
Just a suggestion
J Man

Hey J man

i agree with you, but since the model i made has only 1 bone (2 counting the root ) it would only rotate at that point.

i wasn't going to spent to much time on the model ...it's just to get the idea of movement.

it anyone else has a better example of a model i'm all ears

thanks

Steve

Hiya Steve!

The Pendulum looks great. The only notable discrepancy I can find is that it looks like the pendulum is 'sticking' as it exits the extremes.

Keep up the great work, I look forward to seeing more from you,
-Josh

Thanks Josh

i took another look at the model ...and Jman was right ...i put the bone in the middle hehe

i moved the bone up to the top end and rendered it again

Steve

Good Job Stinky (you don't mind if I call you that... do you? ) it looks really fluent, very realistic.
Also, your "exercise 1a bouncing ball" was very good. I find it far superior to anything I've even tried yet with that exercise, and I am having a hard time trying to incorporate some of the good attributes you used in your example into my trial.
J man

Back to the jumping lamp...

That desk lamp is tricky. The lamp housing is the biggest part but most of the mass would have to be in the base or the lamp would fall over if you posed it out too far. That has a lot to do with how we make it hop.

But whatever we decide about the center of gravity, in a big leap like this one we really want to see a good arc in there to sell the idea of leaping thru the air.

I time lapsed your jump so we could see the path the lamp is taking. (the red dots are tracking the "knee", the head and base are easier to follow
)[attachmentid=16984]

I like the timing of the anticipation, jump and landing, I think that is working rather well.

but for the most part the lamp is traveling straight to the apex of a triangular path and then going straight down the other side. There really should be a nice parabolic arc to the whole movement in at least one part of the lamp and ideally, all parts of it.

Thanks for your time Robcat

i don't mind going over any of my projects again ( i've been motoring through them because i'm on Vacation from work ..i saved up a month vac and planned on spending 90% of the time right here )

yep i now wish i had a laptop hehe

that was a great example of my jump ( how do you do that ? ...what software are you using ? )

i think i solve the problem. ( i think that was someone's last works somewhere i think lol )

i posted a onion skin of my new jump and curves.

thanks so much Robcat

oh BTW ( how is Animation Mentor working out ? )

i was saving up for that experiance, maybe in a year ( i hope )

Steve






Steve or Stinkyu is fine

just check out post 12 of my bootcamp on the bouncing ball ( i even did math on the landing ...each upper arc height is divided by 1.5 ...the ball came in on 200cm , the next height was 133cm ...i did the same for the bouncing across the ground )

hope that help out some ( see my post on your boot camp too )

steve

And now my ABC Level 1 Movie

2 balls interacting


Steve

ABC Level 2 Mr walk ....walking

now walking was tough for me as a child ...and it's not any easier in 3d

tell me you guys think of this basic beginning

i included a side rendered view and left /right leg curves


thanks

Steve

i walked away from the project and came back ( i didn't like the leg spacing )

hehe

so lets try that again


Steve

ABC L2 b Mr walk hopping on 1 foot

side view and normal render ( from above )

thanks

Steve

That looks pretty good Steve. Just watch the sinking toes.

thanks Dhar

just those feet are sooooo long hehe

Steve

here's my fix

thanks again Dhar

Steve

ABC Level 2 C Mr walk stepping casually to the side

i included front view render and thru the camera view

thanks

Steve

p.s.

i found a new tool to help me round those curves ...i found a clear plaste ( came with the monitor ...i'm such a pack rat ) and with white broad marker, and i'm ploting my movements with it

i know what your going to say ...there's a onion skin option for that ...but i don't want to look at every bone st one time ...the hop was just to busy to see anything


the marker help me look at one bone at a time

Hi Steve!

Nice sidestep you got there! The really like the main motion and timing of the body, but I think they're both too exaggerated. It's great that you know how to exaggerate, however, if you've going for realism see what happens when you make the main body movement and timing a little "tighter"

Keep it up!
-Josh

thanks for the tip Josh

i did changed the body movement and yes you're right... looking at the first one and comparing it to the second try ( the first one ...Mr walk was moving like a little dance step )


here's part 2

Steve

so again i walk away and come back to the sidestep.

but i keep wondering why does it look so ( for lack of a better word ) FLAT

then it hit me ....there's no head bobble...

ok now i think this is better

Steve

Nice if you want to bring even more life into it try a rotation clockwise when he raises his feet and conuter clockwise when he raises the other foot. Try a side side yourself in front of the mirror hold a brom handle or stick accross your hips and try to side step without droping or raising the stick. you see then what I mean

Thanks for your thoughts PF_Mark

I tried some roatating of the feet and the body ...it's hard to see but he's pointing to the area where his foot is landing ...then back to looking to the other foot.

i just notice when i do the action ... i don't do nice curve motions ...( my foot ) i tend to go straight the point

i hope this is alittle less flat

Steve

Hey, the jumping lamp looks much better!


There's still several opportunities to plus the poses and arcs. Notes on the movie.

[attachmentid=17095]

I made some comments on not exceeding balance points here...

http://www.hash.com/forums/index.php?s=&sh...ndpost&p=176641

that you may want to consider if you tune the arcs, although the lamp character seems to be more plausible in far-forward and far-backward poses than the ball character is.