14-04-2021, 10:49 AM
(This post was last modified: 14-04-2021, 11:09 AM by josemendez.)
Hi Janik,
I'd say the culprit is your constraint settings: you're using 4-6 iterations for most of them, and using parallel evaluation too.
The thing with parallel evaluation mode is that it converges much more slowly than sequential, that is, it gives more stretchy results. This forces you to use more iterations to get a result similar to what you'd get with sequential mode, which makes it more costly.
Note that "parallel" in this context doesn't have anything to do with multithreading, it refers to the way constraint adjustments are applied to particles: in parallel mode all constraints are solved, then their results averaged and applied to particles. In sequential mode, the result of solving each constraint is immediately applied after solving it. In physics literature parallel mode is known as "Jacobi", and sequential mode as "Gauss-Seidel".
As a result, parallel mode gives smoother but more stretchy results. You should always use sequential unless you got a very good reason to use parallel (such as avoiding biasing). See:
http://obi.virtualmethodstudio.com/tutor...olver.html
Also, using substeps is generally better than using iterations. When you need to increase simulation quality, you should just increase the amount of substeps. Then maybe fine tune each individual constraint by adjusting iteration count. See: http://obi.virtualmethodstudio.com/tutor...gence.html
So I'd start with 3 substeps, 1 iteration for all constraint types and set them all to sequential. That should both look and perform better.
I'd say the culprit is your constraint settings: you're using 4-6 iterations for most of them, and using parallel evaluation too.
The thing with parallel evaluation mode is that it converges much more slowly than sequential, that is, it gives more stretchy results. This forces you to use more iterations to get a result similar to what you'd get with sequential mode, which makes it more costly.
Note that "parallel" in this context doesn't have anything to do with multithreading, it refers to the way constraint adjustments are applied to particles: in parallel mode all constraints are solved, then their results averaged and applied to particles. In sequential mode, the result of solving each constraint is immediately applied after solving it. In physics literature parallel mode is known as "Jacobi", and sequential mode as "Gauss-Seidel".
As a result, parallel mode gives smoother but more stretchy results. You should always use sequential unless you got a very good reason to use parallel (such as avoiding biasing). See:
http://obi.virtualmethodstudio.com/tutor...olver.html
Quote:Parallel mode converges slowly and isn't guaranteed to conserve momentum (things can sometimes gain energy). So use sequential mode when you can, and parallel mode when you must.
Also, using substeps is generally better than using iterations. When you need to increase simulation quality, you should just increase the amount of substeps. Then maybe fine tune each individual constraint by adjusting iteration count. See: http://obi.virtualmethodstudio.com/tutor...gence.html
So I'd start with 3 substeps, 1 iteration for all constraint types and set them all to sequential. That should both look and perform better.