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Creating vector fields for particular effects

Hi,

I want to know how vector fields are created for effects that too place the Unreal Engine Features Walk through?
https://youtube.com/watch?v=acR4n6lJEdQ
The Ice effect somewhere around 3:10.

I got some idea on maya fluid dynamics and how to create a vector field from it.

There’s a plugin for Maya in the Unreal Engine install directory (under \Engine\Extras\MayaVelocityGridExporter) that you can use to export your grid. You can either do a single frame, or a sequence - but I’ve yet to see how to plug a sequence into Cascade. It only seems to accept a single static grid at this point.

Basically, all you’re exporting from Maya are the velocity values of each voxel. Density etc aren’t used in any way once the grid leaves Maya.

How did they created the vector field for that circular ice effect? I am a programmer and don’t know much about Maya. I read some guides on fluid dynamics though. Those particles that get arranged in circle how is it done using fluid dynamics in maya?

A VolumeAxisField connected to the fluid grid will do this. Set the volumeShape on the volumeAxisField to torus, and set the alongAxis to 1.0. Set everything else to 0. That ought to swirl the fluid around into a circle.

If you give me the timecode in the video where the effect is happening, I might be able to give you a better idea of what is happening simulation-wise. Right now I can’t seem to find the effect you’re talking about.

The effect that takes place at 3:25

Can we make fluid pass through a pipe in Maya of a particular shape and bring that vector field to UE4? What kind of effect will it give?

Okay, that looks like the particles are actually created in a ring, then use a field with some turbulence in it to spread them out into tendrils.

You could put a pipe collision object into your Maya fluid, and force the fluid through it - however I’m not sure how well this’d behave in Unreal. You’d probably have to have the particles collide with some geometry in your Unreal scene for it to work. Getting Maya fluids to go through pipes is always tricky however, and usually requires a pretty high res voxel grid to work.

In unreal, can particles be emitted in the shape of a static mesh? Is there any functionality to do something like that?

For the ring, you can use a Cylinder location module on your particle system. You can emit from meshes, but it’ll need to be a skeletal mesh. Even if it isn’t actually a character, and is just a static mesh pretending to be a skeletal mesh, this ought to work.

Or i can write code to spawn those particles in a ring randomly. I just need to check how random spawning of particles works in code. Then I can do it.