HELP Fluid Effects?

[Matty]

Is there a way to make fluids interact with other fluids while colliding with objects? I am using the wind tunnel fluid example. Also is there anywhere I can get REALLY cool wind simulation type fluids? I am doing a site analysis on an architectural project and would appreciate the help.

[stephanmaya]

To make fluids collide, turn on self collide. The best wind results would come from a combination of the UNIFORM field, Air, Newton, Turbulance and the internal noise. You need to play with all of them to get the best results.

[Matty]

stephanmaya,

I do not know that much about fluids. Can you explain more on how to get good wind simulation? I cannot find self collide. Again I am running a simulation across a site, through trees, and mapping the results of the wind flow.

[stephanmaya]

Maya's fluid effects, although nice visually, is lacking somewhat in the department of running water. The best advice I could give you is to use RealFlow, which is an awesome fluid simulator. The effects you can get from that is amazing.

But it costs money, so I'll run down some of the attributes of fluid effects:

Its usually a good idea to have a volume emitter. That way you can control the shape of the flow.

I always add a gravity field straight away so that I can see its effect.

Begin with a low resolution, so that it computes easy. You can increase the resolution later on as needed.

Under Contents Method, set Density to Dynamic Grid; Velocity to Dynamic Gric; Temerature to Off(zero); Fuel to Off(zero); and Falloff Methos to Off(zero);

Under Display set the shaded display As Render.

Under Dynamic Simulation, set the Gravity to about 9.0 or 9.8. Its a good start point since you already have a gravity field in your scene.
Leave everything else to zero.

Make sure Conserve Mass; Use Collisions; Use Emission; Use Fields are turned on.

The rest is now only about tweaking it. Just make sure under Surface > you turn your particles from Volume Render to Surface Render. Turn it to Soft Surface. You'll have to play with the Threshold and the Tolerance yourself, since I don't know the scale of your simulation.

Now you need to create your collision objects. If the geometry it quite dence, rather create a lo-poly or nurbs object that is basically just a collision object that won't be rendered. Don't make it collide against a heavy detailed tree trunk. Rather use a nurbs cylinder.

Now play your simulation and see what it does. If you want it to do something else, just add more fields like Uniform, Newton, Air, Turbulance. Turbulance especially, because it allows you to create that randomness of water.

When water slashes, you'll need to create additional Hardware particles for that. Use multispray with at least 15 passes. That way you'll get a nice effect. You would however need to composite those.

You'll also need to play around with the shading to get it to look like water. If you look at my printscreens, I've just made it green with some white foam. It needs specular, a lot and reflections.

I'm sorry if I confused you with the Self-Collide. It's a Realflow term. But if you made sure that Conserve Mass; Use Collisions; Use Emission; Use Fields are turned on, then you'll get a nice effect.

I hope this is what you needed. If not, please shoot me another message and I'll see where I can help.

All the best and good luck,
Stephan.