Hot as a force

[Sempai]

How can i use hot as force in H12 flip fluid simulation.....

My link

[ssh]

Actually it's Naiad, not Houdini.

Edited August 16, 2012 by ssh

[Solitude]

Actually it's Naiad, not Houdini.

Yes, but he wants to accomplish the same thing in Houdini.

You can do it a few ways -- I think this is the easiest -- first make sure the HOT has a v attribute. You can trail sop set to compute velocity, with a multiplier of .042 for 24fps. You can then use shelf tool: Populate Containers / Pump From Object and point it to the HOT object and flip object -- it will basically creates a velocity volume that then moves around the fluid particles based on the HOT geo. You'll want to lower the resolusion size on "create_v_volume" node that was created on your HOT object. Then, you'll prob also want to modify the SDF From Geometry -- minimum distance to make the range a bit bigger, and same for Sample Distance on the velocity volumes tab of that node as well. If all goes according to plan you should have ocean waves in the flip sim. Also it will be a bit more accurate to the HOT mesh if you use the hot geo to clip the initial state particles, but that's up to you if you need it. If needed I can upload a file later tonight...

Edited August 16, 2012 by Solitude

[nran]

Is there any way if we don't use vel as force in Houdini???? if use vel from HOT surface, 1, the flip surface is not going to match with HOT exactly, 2, in order to match with HOT, we need to have very detailed "vel resolusion" from HOT surface, than can be very slooooooooow in flip sim and hard to control, (at the top of wave,some flip will fly away from the surface)

"clip the initial state particles", are you talking about to subtract the particles which goes outside the SDF geo, so that we can manually maintain the flip particles to have the same shape as the HOT? ummm...this might be a good idea....

Edited August 17, 2012 by nran

[Solitude]

Is there any way if we don't use vel as force in Houdini???? if use vel from HOT surface, 1, the flip surface is not going to match with HOT exactly, 2, in order to match with HOT, we need to have very detailed "vel resolusion" from HOT surface, than can be very slooooooooow in flip sim and hard to control.

looking for another way to do this in stead of using vel. SDF?

You can just displace the points with the ocean sop inside of a sop solver, but since you're just explicitly setting the positions, I don't know what it'll do to interactions with objects and such. Pretty sure that won't won't work right. I usually do the vel field (doesn't have be very hi resolution to get general ocean motion going on), and then post-sim I'll add ocean sop as well to the mesh, only on the surface. Like, if a character is interacting, you don't want all the splashes to be affected by the ocean sop, so you have be creative with the masking of the ocean sop either with speed or height (or both).