guide the sim by a spline

[Ivaylo Katev]

[victorwol]

I was actually thinking about this today, that it would be great if possible. And now I find this thread, but I see nothing posted other than the title, but I'm looking on my phone, is there anything attached to the thread I'm not seeing?

Thanks.

[victorwol]

Oh.... I see that now on my PC... I totally need this, how??? when??? I can totally use it for the wine simulation im doing....

[Ivaylo Katev]

there is a new helper, called "follow path", create an instance, create the spline (standard max spline) and select it in the follow path helper
about the simulation - it's better to switch off the gravity, to not perturb the spline filed. put a source near to the spline beginning.
keep in mind that this feature is not finished, and eventually your simulations may change the behavior in the future

[victorwol]

Thanks! You know what would be VERY cool! To have a FDD deformer, the problem with MAX one is that once is applied it converts all to polygons and some effects that happens at render time like the cutting of the mesh against a glass for example, then it does not happens anymore. Also MAX FDD for some reason tends to deform the whole sim a bit even if you don't deform the cage at all. What I'm trying to do, which I hope the spline helps, is to have that splash that comes out of the wine glass to be a bit wavy, it goes all to the left, but I want to turn to the right a bit, it will be more gracious, this is to render a still anyway.

Can, or will the spline, let particles run along it and then escape and continue at the end of the spline? Or will they be trapped by the spline, I think I saw on your example that liquid sort of reach the end and do not continue and stay there. Does it makes sense?

[Ivaylo Katev]

at this moment the follow path will affect the entire liquid, not only the splash, there is no limitation and decay yet.

[PIXELBOX_SRO]

were upgrading to phoenix 2 now which we need for a very specific project and this is EXACTLY what we need it for.
Will this be available when we download the software or is this feature part othe nightlies?
Cheers!

[Ivaylo Katev]

yes, this is available in the nightlies.

[Swihartc]

If my other post shows up, delete pls I had a question about whether or not anything specific needs to happen between liquid and smoke simulator to get this to work. I can get the liquid simulation to follow spline perfectly, no problem. The smoke simulation will not follow. Gravity is off, made long convection time, resolution is decent, step size is good. The smoke just emits from emitter and drifts down to floor without the spline controlling any particles.

[Paul Oblomov]

I think u have missed the boyancy. Set to -10

[Swihartc]

Sweet, thanks Paul. Knew there was something, but what!

[Ivaylo Katev]

yes, we are planing to remove this requirement, but for now the force is just gravity like force, and the gravity does not affect the smoke if no buoyancy is assigned

[Syclone1]

Ive been trying to achieve something like the liquid following a path like you did Ivaylo but I can not get it to adhere properly to the spline, is there any chance I can get some sort of tutorial on how to set that up or even the scene file for the one you posted? Im currently running on a demo of phoenix as Im trying to make a proof of concept rendering and that particular scene is exactly what I need...

-dave

[Ivaylo Katev]

there is no tutorial, bu i can attach the scene.
all the forces affecting the liquid are harder to control compared to the forces guiding particles in particle flow for example. the reason is that the liquid has complex dynamics, that can oppose to the force efforts.
there main factor that makes the liquid behavior unpredictable is the inertia, it makes the liquid to pass behind the point of attraction, for this case this means when the liquid is approaching the spline, it will not stop reaching it, but will go behind the spline. there is a parameter that can control how strong the liquid is pushed to follow exactly the force filed, this is the "strength" parameter. when this parameter is 1, the liquid velocity gets immediately the values in the UI, it gives 100% control but the liquid does not behave like a liquid anymore, it turns into particles following the field. you have to balance between the freedom of the liquid and the pursued behavior.

[Syclone1]

Awesome, thank you for the file and the explanation. fortunately for these guys it doesn't have to be physically accurate as long as it "looks" believable and since this is for horizontal drilling and showing whats happening 3400m below the surface I have a little room for artistic impression lol. Hopefully Ill be able to sell this and get the ok to buy phoenix, Im having far too much fun with it!!