How can I prevent the Grains from shrinking?

[Masoud]

Hi guys,

I need the grains to preserve their basic shape, but after simulation, it starts to shrink.

How can I fix this?

 

Thanks for helping.

[Librarian]

int n[] = pcfind(0, 'P', @P, @pscale*2, 100);

vector change = 0;
float weight = 0;
foreach (int npt; n)
{
    if (npt == @ptnum)
        continue;
    vector op = point(0, 'P', npt);
    float d = length(op - @P);
    if (d < @pscale*2)
    {
        change += normalize(@P-op) * (@pscale*2-d)/2;
        weight += 1;
    }
}
@P += change / weight;

int n[] = pcfind(0, 'P', @P, @pscale*2, 100);

vector change = 0;
float weight = 0;
foreach (int npt; n)
{
    if (npt == @ptnum)
        continue;
    vector op = point(0, 'P', npt);
    float d = length(op - @P);
    if (d < @pscale*2)
    {
        float omass = point(0, 'mass', npt);
        float ratio = omass / (@mass + omass);
        change += normalize(@P-op) * (@pscale*2-d) * ratio;
        weight += 1;
    }
}
@P += change / weight;

if (i@has_pprevious)
    @v = (@P - v@pprevious) / @TimeInc;

float ratio = omass / (@mass + omass);
change += normalize(@P-op) * (@pscale*2-d) * ratio;

JEFF LAIT- MASTERCLASS ...I think

[Masoud]

Thanks "Tesan" for the reply, but sorry I didn't get that

[Librarian]

Please post A file @Masoud

[Masoud]

Hello;

Here is my scene.

KeepShapeOfGrains.hip

[Ultraman]

18 minutes ago, Masoud said:

Hello;

Here is my scene.

KeepShapeOfGrains.hip

Here u are Masoud maybe is that ur means 

KeepShapeOfGrains.hip

[Masoud]

Hi Ultraman,

My simulation is based on the "POP Solver", so I can't use Vellum.

 

[Masoud]

I know I can use the "Awake node", but how can I make the grain pile harder to collapse, without using "Awake"?

Edited June 23, 2021 by Masoud

[Ultraman]

On 6/22/2021 at 11:55 AM, Masoud said:

Hi Ultraman,

My simulation is based on the "POP Solver", so I can't use Vellum.

 

POP Grain 

GrainHold.hip

[Masoud]

Hi Ultraman,

Your "Point Separation " is very low resolution. If you change it from 0.1 to 0.01, then the grain shape will collapse.

[Ultraman]

On 6/26/2021 at 3:28 PM, Masoud said:

Hi Ultraman,

Your "Point Separation " is very low resolution. If you change it from 0.1 to 0.01, then the grain shape will collapse.

maybe need to increase stiffness or iteration when u add more point .

[Masoud]

Hi guys,

I found this helpful document on the SideFX help page:
https://www.sidefx.com/docs/houdini/grains/stablepile.html