[PD] Cymatics/Chladni figures simulation

[Martin Peach]

Cesare Marilungo wrote:
> Martin Peach wrote:
>   
>> Charles Henry wrote:
>>   
>>     
>>> The sand still could be tricky... you would maybe have the individual
>>> particles at random locations, initially, and compute a gradient of
>>> the vibrations to determine movements.
>>>   
>>>     
>>>       
>> When I saw the sand arranging itself I thought "cellular automaton".
>>
>> Martin
>>   
>>     
> I thought that the patterns and the various configurations in chladni 
> figures depend on the materials used.
>
> Am I wrong?
>
> c.
>   
The patterns probably depend on the stiffness of the plate/membrane as 
well as its shape, and the grain size and density of the sand. By 
analogy with the Karplus-Strong vibrating string, which is a 
one-dimensional CA, usually the stiffness of the string is ignored. 
Also, the grain size would be the same as the pixel size and the density 
would be ignored. I see it as being like 2D version of the KS waveguide, 
with the superimposed grains moving in each time step towards the 
neighbour whose vertical acceleration is the lowest among 8 neighbours. 
Apart from the difficulty of doing a 2D KS, there is the further 
complication of an external frequency forcing (maybe introduced at the 
edges of the plate?).

Martin