2D Curve metaball

[odforce123]

Hey, 

 

I'm looking for a way to create a setup that behaves like metaball but on curves, so basically my idea is to create a setup like in the reference images, where I scatter random points and copy circle shapes to points that have a pscale set based on the distance to a closest point to avoid intersection, and these circles are somehow combined with a distort form between them, like in metaball. I am very curious how you would approach something like this and thank you in advance for any advice!

 

In the attachment I'm sharing the images I found in simillar setup but done in Rhino.

 

[Librarian]

How to feed into this Code pscale for points  from 2 input ?
 

int pntcnt = npoints(1);
float accum = 0;
for(int i=0; i<pntcnt; i++)

{
    vector tarpos = point(1, "P", i);
    float dist = distance(tarpos, @P);
    float falloff = fit(dist, ch('start') , ch('end') , 1,0);
    accum = max(falloff,accum) ;
   
    }

@Cd = set(accum, 0, accum/4);

 

[dleonhardt]

I would start with actual 3D metaballs and take a slice of them to get curves.

dl_2d_metaballs.hipnc

[Librarian]

@odforce123 More Control This and This .

 

Edited March 13 by Librarian
REZULTAT

[konstantin magnus]

Hi Tomek,

you could use smooth minimum functions: https://www.shadertoy.com/view/DlVcW1
Article: https://iquilezles.org/articles/smin/

Here is an example for Houdini:

float r = chf('radius');

function float smin(float a, b, k){
    k *= 1.0/(1.0 - sqrt(0.5));
    return max(k, min(a,b)) - length(max(k - set(a,b), 0.0));
}

float dists[];
int pts[] = pcfind_radius(1, 'P', 'pscale', 1.0, v@P, 10.0, 2, dists);

float d = smin(dists[0], dists[1], r);

f@dist = d;

 

metaball_2D.hipnc

Edited March 13 by konstantin magnus

[konstantin magnus]

Another example using COPernicus' SDF tools.

 

circles_metaball_02.hip