Hey,
as you can imagine out of the Headline, i'm trying to solve a large number of objects with the bullet solver in houdini.
(The task is to compare bullet with a solver written on my own).
Now i am doing some memory tests and found out that the memory usage which bullet has, is not growing linear with the number of objects.
Here some measurements:
Static object: grid with 6400 Spheres on it.
Tests:
Dynamic Obj. – Mem Usage
12 – 1,1 MB
98 – 110 MB
980 – 811 MB
5600 – 23.299 GB
8000 – >32 GB
Does anyone has a idea why?
I should go into detail about this in my Thesis and i have totally no clue why bullet behaves that way, in this special case…
I attached a example file.
Thanks in advance
Found 6 posts.
Search results Show results as topic list.
Houdini Lounge » Houdini RBD Bullet used mem grows not linear with num Object
- StefanReinhardt
- 6 posts
- Offline
Houdini Learning Materials » Accuracy of Bullet Collisions
- StefanReinhardt
- 6 posts
- Offline
Houdini Learning Materials » Accuracy of Bullet Collisions
- StefanReinhardt
- 6 posts
- Offline
Thanks that helped for the collision of the spheres itself.
The collisions with the static spheres on the other hand doesn't look as I expected. Especially they do not stay on them (as i would expect)
A perhabs complete other question, why does the simulation gets more instable if I turn up the substeps…
The collisions with the static spheres on the other hand doesn't look as I expected. Especially they do not stay on them (as i would expect)
A perhabs complete other question, why does the simulation gets more instable if I turn up the substeps…
Houdini Learning Materials » Accuracy of Bullet Collisions
- StefanReinhardt
- 6 posts
- Offline
Hey,
i have a perhabs very noob question.
i have to compare the bullet solver with one written on my own for gran dynamics. Therefore i need very small objects (5 mm) colliding with each other.
So far so good. When they are colliding with each other, the interpenetration is very high. I want them not to interpenetrate…
The most basic idea i have (more substeps so smaller timestep) doesn't work. The more substeps i make the more instable the simulation gets.(Even with a timestep of 10^-5) I also tried to play arount with the Volume Collision parameters with no sucess so far.
Does somebody has any Idea how to solve this problem?
Thanks in advance
PS Appended a demo file where you can see the problem
i have a perhabs very noob question.
i have to compare the bullet solver with one written on my own for gran dynamics. Therefore i need very small objects (5 mm) colliding with each other.
So far so good. When they are colliding with each other, the interpenetration is very high. I want them not to interpenetrate…
The most basic idea i have (more substeps so smaller timestep) doesn't work. The more substeps i make the more instable the simulation gets.(Even with a timestep of 10^-5) I also tried to play arount with the Volume Collision parameters with no sucess so far.
Does somebody has any Idea how to solve this problem?
Thanks in advance
PS Appended a demo file where you can see the problem
Houdini Lounge » RBD-Distance between Objects
- StefanReinhardt
- 6 posts
- Offline
Hey rafaels,
thank you so much that worked.
Just for the record if anyone else will have the same problem again.
I'd also turn down the collision padding of both objects so that the sphere stopped (almost) on the plane. but i had also to add more substeps then so the ball didn't fell through…
thank you so much that worked.
Just for the record if anyone else will have the same problem again.
I'd also turn down the collision padding of both objects so that the sphere stopped (almost) on the plane. but i had also to add more substeps then so the ball didn't fell through…
Houdini Lounge » RBD-Distance between Objects
- StefanReinhardt
- 6 posts
- Offline
Hy Guys,
I have a, perhabs very noob, question.
I'm currently writing my Thesis where I have written a particle solver.
Now I want to compare my solver to the RBD solver in Houdini.
I want to set up the same scene with my solver and the RBD solver and have a look at the differences…
So long story short, i have trouble setting up the RBD Scene correctly.
I tried just one (very small) RBD Object (Sphere) falling on a Static Object.(Grid)
But it doesn't hit the Grid. It stops a bit above the grid and after bouning back and getting into a stable state it falls through it…
I attached the scene. Has anyone a Idea why this is happening? And how i can fix this? (Wouldn't be a problem for me if it isn't fixable but a reason for that, because this would also be good result for me, but I think i am missing something…)
Thanks everybody
I have a, perhabs very noob, question.
I'm currently writing my Thesis where I have written a particle solver.
Now I want to compare my solver to the RBD solver in Houdini.
I want to set up the same scene with my solver and the RBD solver and have a look at the differences…
So long story short, i have trouble setting up the RBD Scene correctly.
I tried just one (very small) RBD Object (Sphere) falling on a Static Object.(Grid)
But it doesn't hit the Grid. It stops a bit above the grid and after bouning back and getting into a stable state it falls through it…
I attached the scene. Has anyone a Idea why this is happening? And how i can fix this? (Wouldn't be a problem for me if it isn't fixable but a reason for that, because this would also be good result for me, but I think i am missing something…)
Thanks everybody
-
- Quick Links