Thin plate FLIP fluid collisions

[JaydenDP]

Hi,

I'm trying to figure out a way of getting my flip fluid simulation so be affected by a static object I have in the simulation, but using thin plate collision detection (i.e. "use volume based collision detection" is toggled off in the static object).

In my test scene I have a deforming grid, moving in a direction, but when my fluid particles hit the surface they react as expected EXCEPT for inheriting the velocity of the static object (which isn't static, and deforming geometry is toggled on). So they do collide and then just sit there as the moving grid slides underneath it without affecting it.

Any ideas would be much appreciated, thanks in advance.

Here is a test hip file as well in case my powers of description have failed me.

thinPlate_FLIP_collisions.hip

[JaydenDP]

Here's a quicktime of what im talking about as well.

slidingProblem.rar

[JaydenDP]

Here's a test I did in like 2 seconds in maya with a very basic particle fluid sim colliding on a moving grid and it works fine! Why cant I get the same thing to happen in houdini?

Quicktime attached.

mayaParticleFluids.rar

[tjeeds]

Hi Jayden, I'm happy to be corrected but as far as I'm aware FLIP doesn't support thin-plate collision, this is true in Naiad as well. You can use Volume based collision detection if you just add a bit of depth to your surface and make a decent collision volume out of it.

[JaydenDP]

Hi Jayden, I'm happy to be corrected but as far as I'm aware FLIP doesn't support thin-plate collision, this is true in Naiad as well. You can use Volume based collision detection if you just add a bit of depth to your surface and make a decent collision volume out of it.

Hi there, yeah I thought that might be the case, but I've tried the same file with SPH and still the same problem. The problem seems to specifically with FRICTION and THIN PLATE collisions. I get friction using volume collision with SPH and FLIP, but with thin plate, there's no friction with SPH or FLIP. Bug? maybe a workaround?

Thanks for the comment.

[JaydenDP]

Hmm, no one seems to know. I'm gonna say its a bug then?

Im surprised how much trouble houdini has doing non-volume based collisions, when every other package uses face collision by default and works fine.

Back to the drawing board .

[JaydenDP]

Hi Guys,

Well for those who are interested, my file was submitted to sidefx a while ago. And I've just heard back that the problem was indeed a bug, and its been fixed in todays build update.

Thanks for all the views and downloads

Jay