Cascading smoke

Phoenix Phoenix :: General
1

I am using a higher density grid close to camera with a larger grid covering most of the scene at lower resolution. I have set the simulators to cascade and it is simulating after the first attempted cause a crash. But you can see I’m getting virtually nothing out of this main simulator.

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The main sim is chockablock with the smoke clearly billowing up against the edge of the grid

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Is there a setting you need to tweak to make this work properly?

It seems like all it is doing is sharing the sources (which it would anyway), because none of the existing smoke is travelling into the second grid. The visible smoke (gpu) is coming off the terrain, which is a source for the first grid.​​

EDIT: Is it perhaps because these are writing to VDB format?

2

Hello,

You can find a sample scene along with some explanations how Cascade sims are working for Fire and Smoke simulations here - Phoenix for 3ds Max

3

Using Maya, there is no cascade example for Maya.

4

Ah, sorry - here is the Maya version - Phoenix for Maya

5

Looking up this topic of creating cascading simulations for Fire and Smoke.
The link above takes you to the Maya documentation, However it doesn’t take you to an example of fire/smoke cascade connecting.
Have found likes and tutorials about doing liquid sim connections. (Haven’t tried that yet).
However the menu item to connect cascading simulations doesn’t seem to exist.

Ok. just tried switching to liquid sim mode to see if the menu item appears. It did not.

My use example would be a lengthy missile trail.
Along with desiring the above example of a large smoke/fire sim, with the ability to create in byte sided chunks.

I do see the gridUseCascade, which seems to be on by default in the FireSmoke simulator.
But oddly it shows “adapt by” set as “Liquid”
And unsure how you would set the gridCascade?

Also to note as above, this is being attempted or experimented with in Maya (2025) with the latest PhoenixFD 5.24 and VRay 7

Thanks if you have any information or links to study.

6

OH.. just saw where cascading is only for liquids.

Is there a solution for smoke and fire?

7

FOLLOW UP: 02/20/26 11:20
- I don’t believe there is any solution needed.

Having the time this morning to experiment, here are aspects discovered.

- gridUseCascade is on by default.
- Separate sim domains seem to always respect scene elements such as FD sources, and I believe intersecting simulators. (Still experimenting.)

Will keep experimenting to see what results can come of it.
Thanks for your patients doctor.

8

Here’s an updated link for the Maya template scenes. Look for the Fire/Smoke Cascade simulation title and download the scene.