Houdini 18.5.462 on linux, ubuntu

when simulate 6000 bullet pieces, at first frame the memory usage is at 50G/64G. this only happen when the bullet object is very very small, at 10cm in diameter and divided as 6000 pieces. But if i simulate for a 100cm（diameter）object also divided as 6000 pieces, the memory usage is just 5G, very efficient, and very fast, i know bullet is good for big simulation, but is there a way to make bullet work with a small object sim? like a sphere at 1cm in diameter and divided as 10000 pieces ?? i don't want to use RBD solver.

thanks in advance.

i have attached the hip, be careful, this might make your computer going out of RAM.

Im guessing here since I cant look at your file.
There are parameters on the bullet object called "collision padding" and "shrink collision geometry". These are in absolute numbers, so in the small scenes all the collision objects intersect on first frame.

mawi
Im guessing here since I cant look at your file.
There are parameters on the bullet object called "collision padding" and "shrink collision geometry". These are in absolute numbers, so in the small scenes all the collision objects intersect on first frame.

I have change those setting and tried many time, with different one, still not working, the RAm usage go up very quickl, by lower the "collision padding" and "shrink collision geometry", still the same result. taking 50G Ram quickly.

i'm thinking, maybe this is a bug?

Hello
As mawi said decrease collision padding and also your node tree wasn't connected correctly
after those change it run smoothly :

Benjamin Lemoine
Hello
As mawi said decrease collision padding and also your node tree wasn't connected correctly
after those change it run smoothly :

Actually, when the sphere hits the ground, the RAM usage go high again, i did the same thing as you showed me here.

with constrain Network it runs before hits the ground, but when the sphere hits the ground, the RAM usage go crazy again.

Benjamin Lemoine
Hello
As mawi said decrease collision padding and also your node tree wasn't connected correctly
after those change it run smoothly :

did you make the sphere hits the ground on your side?

Yes the sphere hit the ground and everything was working.. Did you decrease the collision padding ?, just try with zero padding; for this kind of sim it's ok! The default correspond more to big building piece than to very small chunk. If it got impossible stuff to resolve it will make your ram crazy , you've got to give the solver a bit of help too
If i recall correctly you didn't relax at all the point in your scatter , try a relax of 1 even decreasing the radius scale it will avoid super super small piece ....

Benjamin Lemoine
Yes the sphere hit the ground and everything was working.. Did you decrease the collision padding ?, just try with zero padding; for this kind of sim it's ok! The default correspond more to big building piece than to very small chunk. If it got impossible stuff to resolve it will make your ram crazy , you've got to give the solver a bit of help too
If i recall correctly you didn't relax at all the point in your scatter , try a relax of 1 even decreasing the radius scale it will avoid super super small piece ....

possible to upload your hip? i did all you have suggested, but the RAM is still go crazy

houdini ver 18.5.449

here it is ;
my ram goes higher too
but it work

Benjamin Lemoine
Yes the sphere hit the ground and everything was working.. Did you decrease the collision padding ?, just try with zero padding; for this kind of sim it's ok! The default correspond more to big building piece than to very small chunk. If it got impossible stuff to resolve it will make your ram crazy , you've got to give the solver a bit of help too
If i recall correctly you didn't relax at all the point in your scatter , try a relax of 1 even decreasing the radius scale it will avoid super super small piece ....

Thanks man!

i have upgrade to 18.5.499, everything works fine, the RAM usage is not going crazy.

thanks again for your help,!!!!

thanks