Lava Spray/Burst

[ecarlsen]

Hi all, I’m using Phoenix FD 3.0 for Maya. I’m working on an animation of a volcanic eruption that includes lots of spewing lava and a “curtain of fire.”

Reference here: https://www.pond5.com/stock-footage/...-loa-volc.html

I’ve used Phoenix FD a bit for smoke sims but am at a loss as to where to start with the spraying/spurting lava, which in the reference material appears much finer/more like a spray than blobby. Thus far I’ve had a hard time getting a large number of droplets of varying sizes to spew out in a liquid sim. Everything ends up blobby/stuck together.

Here are a couple of thoughts I had on how to achieve the look:

• To match the reference video, either emit from a long narrow plane, or create a series of emitters so it feels someone segmented with different areas emitting more/less than others
• Have the discharge rate ramp up from a low number so it doesn’t shoot out violently then settle into a low-height burbling fountain-like appearance

Any tips on how best to get started with something like this, or what general approach I should steer toward?

Thanks in advance!

Eric

[ecarlsen]

To further clarify about the "curtain of fire", here is another image of one: https://meggietailor.files.wordpress...rtain-fire.jpg. The one I'm trying to illustrate was 500m long and only 1m wide, so truly a very long narrow strip, like it's coming up from a crack/fissure in the ground.

[Svetlin.Nikolov]

Hey,

Emitting from a long emitter sounds right. Don't use planes or other open geometry - always shell all geometries interacting with Phoenix fluids, especially liquids. You can texture map the emitter's outgoing velocity and animate the map, and then you'd have to get the timing right. If your look is blobby, maybe you don't have enough grid resolution - at 50-100 million voxels it should have the amount of fine details needed for this kind of sim. You can also play with the Mesh smoothing options - if you enable 'Use Liquid Particles', you can adjust the particle size and shrink or inflate the mesh. You could also render both the liquid mesh, and also pick the liquid particles in a Phoenix Particle Shader and render them as points - if you color them via a particle texture, they should look good, and you can also increase the Count Multiplier on the Particle Shader in order to create more particles at render time. You can use the shader from this tutorial as a model for getting an interesting and diverse look of the lava, and you could apply it both to the mesh's diffuse color, as well as to the particle shader's color map slot, if you choose to have a particle shader as well: https://docs.chaosgroup.com/display/PHX4MAX/Lava

Hope this helps

[ecarlsen]

Thanks so much, Svetlin! I will try out these approaches.