AnimationMorph

Alan Kay Alan.Kay at squeakland.org
Sun Feb 17 20:20:26 UTC 2002


Maybe there is an interesting compromise. The holders are nice and 
simple to drag and drop the animations into -- what is the easiest 
way to tie the animations to system events?

Cheers,

Alan

------

At 10:22 AM -0800 2/17/02, Jim Benson wrote:
>  > Jim --
>>
>>  Why not just use holders in etoys? This is the way children do
>>  animations in Squeak ....
>>
>>  Cheers,
>>
>>  Alan
>>
>
>Uh oh, busted. This is a tough room. After Tamikas tutorial, my position is
>indefensible, but ...
>
>There are a couple of reasons for the animation morph. These animations are
>part of a larger sequence of concurrent animations that I run at a
>conceptually lower level of the system. For example, things like window
>close/collapse/move, and Project thumbnail animations that require things I
>couldn't easily provide with etoys based scripts. (Thinking about it, that
>probably means that *I* don't know how to add the animations with etoy
>scripts into the lower level. Maybe I should get some of those smart
>children to do that for me ;-)
>
>This code is a pared down version of the stuff I use, which uses completion
>callbacks and such. It also scales the animation to fit the extent of the
>morph bounding box. Here's where this animation stuff comes from:
>
>What I've been playing with are the ideas of  Craig Reynolds 'Steering
>Behaviors For Autonomous Characters'.
>
>http://www.red3d.com/cwr/steer/
>
>Most of this material is the low level "Turtles, Termites, and Traffic Jams"
>StarSqueak stuff, but from a slightly different perspective.
>
>You hit a collapse box on a SystemWindow (which I don't normally think of as
>part of the etoy world). The window 'collapses' into a thumbnail. The
>thumbnail is then put on a VehicleMorph, which zooms away to some target
>position with a 'follower' vehicle attached.
>
>A VehicleMorph may be programmed with different types (or combinations) of
>behaviors such as 'Arrival'. With an arrival behavior the vehicle moves
>towards a target at some maximum velocity, but arrives at zero velocity,
>that is, it appears to slow down when it gets in proximity to the target. I
>use these behavioural mechanisms to implement the 'slow in, slow out' part
>of animations from the Self work.
>
>[I also use these types of effects when I pick up a window thumbnail in the
>hand. I attach a 'follower' vehicle which just displays the thumbnail with a
>bit more translucency. The follower is programmed with a 'seek' behaviour.
>When I move the hand, the follower 'follows' at a distance dependent on how
>fast the hand is moving. When the mouse is moving fast, a temporal aliasing
>effect appears as a motion blur from the follower as it tries to keep up.
>This is another animation cue taken from the Self Morphic world]
>
>When I expand a window from a thumbnail here's what happens: First a 'poof'
>animation starts where the thumbnail appears. Concurrently the thumbnail
>takes off (with a follower attached to give it a little motion blur type of
>effect), and travels to the center of the represented window. Once it
>arrives and slows down, the represented window expands.
>
>Still, these are pretty lame excuses.
>
>Jim


-- 



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