mikm

10th June 2003 17:49 UTC

metablobs- but different
another metablobs preset, but I wanted it to be different, so I have two sets of blobs- one positive and one negative so its more dynamic (Read the comment). btw- if this crashes try downloading the new colormap.http://www.deviantart.com/deviation/1646190

UnConeD

10th June 2003 22:26 UTC

They don't seem to be very meta :P. Except for maybe around the very edges.

For metaballs you need a concave falloff function for the color. Suppose your falloff function is f(x). Take the sum of f(x)+f(t-x) as you move t towards zero (start so that f(x) and f(t-x) don't overlap) and draw the graphs (e.g. using a ssc x=i*2-1;y=f(i)+f(t-i); where f is your expression for the falloff function.
First we try a linear function f(x)=max(0,1-d); It starts at 1, goes down to 0 and stays at 0 from x>1. Start t at about 2.5 and decrease it very slowly. Notice how the 'shared' area becomes flat between the two.
We'll now try a convex function, which bulges upward: f(x)=if(below(x,1),cos(x*pi/2),0);. It's a part of the cosine function. Notice how now the shared area has a bump in the middle. This is even worse!
Now instead, use f(x)= if(below(x,1),1-sin(x*pi/2),0);
This function is concave (it hangs downward). Now if you move the two functions closer together, you'll get a nice metaballish effect between the two.

The attached preset shows two metaballs approaching eachother, with the slice running through the gray line represented at the bottom. The red lines contain the result after colormapping. It switches between 4 shapes of functions: the 3 above + the mixcurve 1-(3x^2-2x^3).

The mixcurve actually is quite good, because it is convex at one end and concave at the other. So you get both decent blobbing at the edges, but without tiny spheres in the middle.

Yathosho

10th June 2003 22:28 UTC

nice educational preset, ucd :D

mikm

11th June 2003 01:20 UTC

thanks for the explanation...will work on it.

S-uper_T-oast

11th June 2003 04:25 UTC

I understand that UnConeD, I'm going to work on making my own metablobs now.

[Ishan]

11th June 2003 09:34 UTC

Yes your preset helped a lot to understand thanks UCD.:up:

sidd

11th June 2003 14:07 UTC

wow M^2k, that preset is fucking nice. Even if it isnt real metablobings.

Tuggummi

11th June 2003 14:12 UTC

LOL! Anyone else seeing any humour in the fact that UnConeD's educational preset has been downloaded more times than M^2k's own preset :blah: :p

Nice preset M, looks a bit like a preset i did for my next back (which has nothing to do with metablobs though), but grain/scatter/fuzzify effects don't quite fit with solid shapes i think... but that's just me.

sidd

11th June 2003 14:14 UTC

geez, thats what i liekd about it tugg

Tuggummi

11th June 2003 14:18 UTC

but that's just me.

mikm

11th June 2003 16:46 UTC

so maybe i will leave it like this and tone down the scatter or remove it...then I just need to rename it.

[Ishan]

11th June 2003 17:10 UTC

how about fizzy-o-therapist???(jus popped in mind:D )