Le 30/01/2010 03:31, SharkD nous fit lire :
> I've described some different blob functions here:
> 
>
http://www.geogebra.org/en/upload/files/english/Michael_Horvath/Metaballs/geogebra_metaballs.htm
> 
> 
> How would one create a blob function that simulates the way gravity
> works? I.e. the interaction of multiple gravitational bodies.

Looks to me that gravity fields and electric fields are similar (Method
1, the long one).
You would have to add weight (mass) in the equation as the strength of
the field. (similar to using electric fields from different voltage),
also your h would be the sum of vectors, something along

f(x,y,z) = Mass_of_F / sqrt((x-xA)^2 + (y-yA)^2 + (z -zA)^2)
g(x,y,z) = Mass_of_G / sqrt((x-xC)^2 + (y-yC)^2 + (z -zC)^2)
h(x,y,z)/as vect = f(x,y,z).unit_vector(<xA-x,yA-y,zA-z>)
+ g(x,y,z).unit_vector(<xC-x,yC-y,zC-z>)

i = length_of(h);

Notice that with 2 bodies, you have 1 zero.
With more than 2 bodies, even in 2D plane, it's starting to be "interesting"

Of course, that's unrealistic, as it assume ponctual mass (traditional
in physic for low level) and do not take into account the Roche limit.
And it does not take into account the relativity's issues if a mass is
moving fast. (with that set of equations, the fields move faster than
the information limit: c!)

PS: black holes are not responding well to that set of equations either.
(horizon seems to be linear to the mass, not like classical distance we
are used to... )

PS2: gravity does not exist, the earth is sucking.

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