Page MenuHome

Line artifacts in Mantaflow smoke sim when using "Noise"
Confirmed, NormalPublicBUG

Description

System Information
Operating system: Windows-10-10.0.17763 64 Bits
Graphics card: GeForce GTX 660 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 441.08

Blender Version
Broken: version: 2.81 (sub 12), branch: fluid-mantaflow, commit date: 2019-10-19 21:25, hash: rB998c8d18f226
Worked: (optional)

Short description of error
When Noise is activated in a Mantaflow smoke sim, hash line artifacts show up in the early frames of the sim.
With Noise active:


With Noise switched off:

Here's the .blend file:

Exact steps for others to reproduce the error
Create mantaflow smoke sim, bake smoke, bake noise, notice artifacts.

Event Timeline

We don't usually take bug reports in work in progress branches, but I will leave to @Sebastián Barschkis (sebbas) to decide what to do here.
Thanks for reporting and testing the functionalities either way.

I can confirm I can reproduce the problem even at render time.

Yes, thanks for reporting. I will look into this now.

Sebastián Barschkis (sebbas) lowered the priority of this task from 90 to 50.Nov 21 2019, 12:24 PM

@Steve Ernst (steveernst117) @Juan Gea (juang3d) Just tried to reproduce the issue but it seems to be fine now. Can you try it out as well?

@Sebastián Barschkis (sebbas) Yeah, I can confirm the project file looks much better with newest official mantaflow build. Looks like they got the bug worked out.

Okay, great! Closing the issue!

Sebastián Barschkis (sebbas) reopened this task as Confirmed.Feb 12 2020, 8:07 PM

Another file showed up where the "line artifacts" are still visible. Reopening the issue!

Brecht Van Lommel (brecht) changed the subtype of this task from "Report" to "Bug".

I think I have an example file here that has the same issue but in an extreme form, hope it helps with hunting down the bug.

Here the simulation without noise:

And here the same frame with noise turned on:

How to reproduce: Open attached file and bake twice, once with noise disabled and once enabled:

I think I have an example file here that has the same issue but in an extreme form, hope it helps with hunting down the bug.

Here the simulation without noise:

And here the same frame with noise turned on:

I have exactly the same problem. Looks terrible, especially with fast moving flames.