"Bald Eagle" <cre### [at] netscapenet> wrote:
> Le_Forgeron <jgr### [at] freefr> wrote:
>
> > Does the ball really need to be seen deformed ? Can you consider a
> > billiard (pool) ball, or a bowling ball ?
>
> No, of course not - a preliminary version could use a perfectly elastic
> collision with a non-deforming sphere, but I think that the deformation would
> look nice, especially at close range and slow speeds
>
> > Rule of animation & cartoon: when cutting a tree with an axe, do not
> > bother with the frame on which the axe meet the tree.
>
> OK - good to know - That was certainly a concern of mine.   I suppose that might
> greatly simplify the task and shorten the number of frames required.
>
> > There was a bouncing ball in the scene of povray: boing , but you will
> > need any of 3.1 up to 3.6.1 version (of particular interest
> > scenes/animation/boing/bounce.pov )
>
> Thank you very much for that!  :)
> Admittedly, I often forget to look in the /scenes subdirectories where there are
> samples scenes, but as it's not there anyway, I found a copy here:
> http://code.metager.de/source/xref/povray/3.6.1/scenes/animations/boing/boing1.pov

With 3.5 I had installed here, didn't know it wasn't part of 3.7 anymore.

Had to try something with it myself so I used brute force. Probably a bad way to
go about it. Only for 150 frames, beginning at 0 and going to 149; I also used
Cyclic_Animation=on so it would be repeatable.

sphere { 0, 10
 #if(frame_number<2)
scale <1+0.1,1-0.1,1+0.1> #end
 #if(frame_number>36&frame_number<38)
scale <1-clock/3,1+clock/3,1-clock/3> #end
 #if(frame_number>74&frame_number<77)
scale <1+clock/5,1-clock/5,1+clock/5> #end
 #if(frame_number>111&frame_number<113)
scale <1-0.1,1+0.1,1-0.1> #end
 #if(frame_number>=149)
scale <1+0.1,1-0.1,1+0.1> #end
texture{...}
    translate <spherex,spherey, 0>
}

Simply deforms the sphere a frame or two where I found the floor and wall hits
to be, but delayed a frame to look more like a reaction. Not exact, by all
means.
Failed on the final frame, I guess because cyclic drop s a frame. Made it
squeeze before hitting floor. Doesn't seem to matter for the start.

To me the 150 frames is already a slow motion look but when trying shorter
animation the instance at wall/floor hit can get missed.


#default{pigment{blue 1}}#for(I,-1,1,1)
#if(I!=0)cylinder{<I-.3,0,3>,<I-.3,1,3>,.2}#end
sphere{<I-.1,0,3>,.4}#end//bob

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