smoke trails

[Marcus_Litterer]

I had to simulate a missile trail that is very long and the missile is traveling very fast. How would i set up multiple grids in order to simulate the trail. unfortunately I had to use fume which i do not really like that program i prefer phoenix. Also after setting up the grids how do i get them to simulate after the first grid is done automatically. I have watched the tutorial on the cascading smoke grids

[georgi.zhekov]

Hey,

You're exactly spot on - it's best to use cascade simulations for such cases. In order to chain a few simulators to start one after another - it depends if you're using Max or Maya.

In 3dsmax under the Simulation rollout you need to turn on the checkbox "Use script", then press the Edit button next to it.

After this you need to uncomment the following lines below the OnSimulationEnd function

sim = getnodebyname "PhoenixFDFire002"
select sim
A_StartSim sim

Where you need to substitute PhoenixFDFire002 with the name of your second simulator.

If you're using Maya - you can right-click on the Start Sim icon in the Phoenix toolbar and it will prompt you with a simulation sequencer. You just reorder the simulators the way you wish them to start and you run the simulation.

You can check how the cascade is setup in 3dsmax here - https://docs.chaosgroup.com/display/...emplate+Scenes

and here for Maya - https://docs.chaosgroup.com/display/...emplate+Scenes

Cheers,

[Marcus_Litterer]

Ok thank you for the info I will test it out, also do i need to use volume brush or can i be done in any mode surface force or inject since i will be using pflow

[Marcus_Litterer]

One more thing what do you mean by uncomment is there a sample text or screen shot that you could share

[Marcus_Litterer]

Disregard that last statement I ended up figuring it out about the uncomment

[georgi.zhekov]

Yes you will have to use Volume Brush mode. Surface force mode won't work with particles - you can find more about it here - https://docs.chaosgroup.com/display/...+%7C+PHXSource

[JuhaHo]

I'm also working with a similar kind of flying object at the moment. I got somewhat acceptable results on simulation itself when rendered without geometry on backround. However when I have landscape model the trail breaks up when there's geometry behind, but works fine, when there's clear sky. Another issue is that the alpha channel is very weak on the trail. The effect is almost invisible when composed in Photoshop.

[georgi.zhekov]

Can you show us how this looks and your settings?

[Svetlin.Nikolov]

Hey, are you using Aerial Perspective or V-Ray Fog by any chance? If so, check this: https://docs.chaosgroup.com/display/...VRayVolumeGrid

[JuhaHo]

Thanks Svetlin,

This may well explain the situation. If I have a change, I try this tomorrow.

[JuhaHo]

I tested it, but didn't see any difference. Does this have any effect. The trail is part of a xref scene. The I have second Phoenix FD system on my scene, the Ocean, which is part of main scene. It contains a boat drive simulation with nice foam on it. Sometimes the foam is not visible on rendering. If I hide the water, the foam is seen totally behind the boat, not around it.

[Svetlin.Nikolov]

Okay, then back to Georgi's question of showing a screenshot of the issue, because right now we're just guessing.