Sand test, collision jittering issues
Hi, i'm trying to create a simple scene with a box fill of sand and an object that emerge from below.

Fisrt issue is that particles are jittering everywhere.

Second is that a lot of particles go inside the collision object and cause all binded particle to stay attached to it.

I'm reading a lot of thread about jittering and i'm trying to first solve this issue.
Also studying more the " sandCastle " scene.

wich is the correct workflow in a situation like this ? 

I'm thinking to create an initial state where the particles are sleeping and than activate particles when the collision object hit them. 

I will post my progress in the next days Maybe with a preview of the viewport and not a complete render  Smile.


Is my first post, hope link are working and the post is in the right place.

Attached Files Thumbnail(s)
Probably i'm too noob for doing this in the correct way at the moment.

Tomorrow i will start from scratch tryng first to fill the box and then adding collision.
For now i can't even do this. it start with the correct volume than all collapse to a thiny volume after few frames.
Hy guys, after studing more I end up with this result and for me is way much better.
The jittering is almost gone and no collision penetration problems at all.

I've played mostly with Mass multiplier in Particle Bind Solver and Mass z-bias inside Partile Physics, first one for collision problems and second one to help stacked particles. I've also increased the Steps in solver settings. And give 25 frames to the solver to settle up.

Probably I do not understand perfectly what those settings do alredy but it is a step forward for me. I'm also not sure that this is the right way to handle a simulation like this. 

Wich workflow do you suggest or use? Is there something that I can do in a better or optimized way ?

I've also added a surface test to remove the penetrating particles on all colliding objects.

Another thing that I struggle to understand is how to manage the transition from big test grain to final fine grain. Is not easy for me to understand how it will change. I also understand that probably i do not have enought ram to simulate ultrafine sand. This size is ok but in my mind i will have something smaller.

Next i will understand and test better the Particle Sleeping settings and how to use PartilceSwitch and Stop operator in combo to completely stop jittering cause I saw this suggestions in different posts.

Feedback and suggestion are obviously welcome.

Here are my result and the flow preview:


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