flip solver with goals

[jumper]

Hi

I have uploaded my first attempt at using the flip solver tools and would appeciate any help or feedback. I am trying to goal the fluid so that it creates a simple platonic shape after a period of being "released". This works up to a point. I have based the goaling mechanism on a Peter Claes tutorial (on goaling with just plain pops) . I have included a slightly modified version of his pop network in the pop solver of the AutoDopNetwork. Is this the correct approach?

At the moment my setup doesn't take into account where the particles are before they are goaled, so the fluid "self-intersects" en route to its destination shape. I guess each particle goal should be based on proximty to the final shape, rather than arbitrarily defined by a point number lookup of a scatter sop. I am not sure what is the best way to do this.

Another problem I'm having is that I want the goals to snap the fluid into shape a lot more suddenly... but without the particles overshooting their goals and oscillating. I have tried ramping up the drag as the particles approach their goals but the change is still too soft - I would like the fluid to "snap" into place more.

Any pointers would be greatly appreciated!

(And thanks Peter for a great tutorial!)

Stephen

example.mov

flipGoal_v01.hip

[Macha]

Try this Stephen.

flipGoal_v02.hip

[jumper]

Try this Stephen.

Hey Macha,

Thanks that is much better!... Just wondering how I could get it to conform to the goal more - I'm not sure what is causing the top of the octahedron to be missing?

Also I was thinking that I should do the attraction from the closest fluid point to the closest point on the goal mesh so that all the particles are not attracted at the same time. The closest particles are goaled first, and then the "attraction" radiates out to the particles further out.

I guess I'll try and use the magnitude of the vector between the particles position and the particles goalpos as a kind of wipe for the force?

Thanks again

Stephen

[MENOZ]

Hey Macha,

Thanks that is much better!... Just wondering how I could get it to conform to the goal more - I'm not sure what is causing the top of the octahedron to be missing?

Also I was thinking that I should do the attraction from the closest fluid point to the closest point on the goal mesh so that all the particles are not attracted at the same time. The closest particles are goaled first, and then the "attraction" radiates out to the particles further out.

I guess I'll try and use the magnitude of the vector between the particles position and the particles goalpos as a kind of wipe for the force?

Thanks again

Stephen

I think that in the macha example the particles are attracted to the nearest point, that should be the reason because they don't cover the entire object.

to control the "snappiness" you could try to modify the velocity vector as it reaches the goal point.

to control wich particle start first you could animate the goalOn attribute per particle.

to have a more "solid" shape you could try to reducing the separation scale in the flip solver, and maybe some other parameters like the particle size, or radius.. I don't know exactly wich of those attribute are considered in flip.. but the idea is to reduce the space between the particles.

I think you don't need to convert a scalar into a vector because what you want to do is scale the lenght of the vector, so just multiply the vector by the scalar. But it's possible that I'm missing something....

Please correct me if I said something wrong

Edited February 19, 2011 by MENOZ

[hatrick]

does anyone know how the pop attribute transfer used in machas example can be translated into the H13 POPDOP world.

 

Thank you!

 

Lucas

[narbuckl]

Here is an example I recently made for someone looking to control particle forces via an SDF of an object, you could easily apply this to the flip solver instead of just the pop solver. Hope it helps.


 

sdfForce_example.hip