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Boiling Fluid? - amperdev - 03-08-2020

Hello, Obi noob here!

I was wondering how would I go about implementing a boiling fluid effect? 

I want to have it so I can activate the fluid to boil and then go back to a normal state.

Is this even possible with Obi Fluid?

Thank you!


RE: Boiling Fluid? - josemendez - 03-08-2020

(03-08-2020, 11:02 AM)amperdev Wrote: Hello, Obi noob here!

I was wondering how would I go about implementing a boiling fluid effect? 

I want to have it so I can activate the fluid to boil and then go back to a normal state.

Is this even possible with Obi Fluid?

Thank you!

Not possible with Obi Fluid. When a liquid boils, it basically starts to evaporate generating bubbles in the process. Bubbles are air trapped inside the liquid, simulating them would require simulating air as a second phase that interacts with the fluid. This is extremely slow to simulate and generally avoided even in offline simulators. It's an active field of research, some advances have been done, but still far away from realtime performance.

Best you can do is fake it adding some perturbation to fluid particles (small upward forces at random places) and/or a regular particle system with bubble billboards.


RE: Boiling Fluid? - amperdev - 03-08-2020

(03-08-2020, 11:08 AM)josemendez Wrote: Not possible with Obi Fluid. When a liquid boils, it basically starts to evaporate generating bubbles in the process. Bubbles are air trapped inside the liquid, simulating them would require simulating air as a second phase that interacts with the fluid. This is extremely slow to simulate and generally avoided even in offline simulators. It's an active field of research, some advances have been done, but still far away from realtime performance.

Best you can do is fake it adding some perturbation to fluid particles (small upward forces at random places) and/or a regular particle system with bubble billboards.

Can't I trigger the Obi particles to stop using gravity so they float off while changing their material color?

As for faking it how would you go about adding force to the liquid? say I'd want it to start boiling when it enters a trigger

Thank you!


RE: Boiling Fluid? - josemendez - 03-08-2020

(03-08-2020, 11:53 AM)amperdev Wrote: Can't I trigger the Obi particles to stop using gravity so they float off while changing their material color?

Yes, but it doubt that would give a very convincing boiling fluid effect. Would look more like colorful zero-g water Indeciso

(03-08-2020, 11:53 AM)amperdev Wrote: As for faking it how would you go about adding force to the liquid? say I'd want it to start boiling when it enters a trigger.

Just write some values in the solver.externalForces array. This is a per-particle array containing the total external force for each particle.

To get contact info for the current frame, subscribe to the solver's OnCollision event. Then you can filter contacts to determine which ones involve the trigger:
http://obi.virtualmethodstudio.com/tutorials/scriptingcollisions.html


RE: Boiling Fluid? - amperdev - 03-08-2020

(03-08-2020, 12:00 PM)josemendez Wrote: Yes, but it doubt that would give a very convincing boiling fluid effect. Would look more like colorful zero-g water  Indeciso


Just write some values in the solver.externalForces array. This is a per-particle array containing the total external force for each particle.

To get contact info for the current frame, subscribe to the solver's OnCollision event. Then you can filter contacts to determine which ones involve the trigger:
http://obi.virtualmethodstudio.com/tutorials/scriptingcollisions.html

Awesome thanks!

just purchased Obi fluid couple of days ago and about to use it now for the first time!

this is going to be fun  Gran sonrisa