Motion Blur is not working on PhoenixFD Fire

[VickyVapp]

Hello All,
We cannot work out how to apply motion blur in this simulation. What is wrong?
There is Velocity channel output in PhoenixFDFire...

We are using Phoenix Fluid Dynamics ADV for 3ds Max 2018 / V-Ray Next Update 2 (4.2)

Thank you.

[Svetlin.Nikolov]

Everything looks in place. Can you send over the scene with a single cache - no other geometry or lighting would be needed.

Also, can you check the exact Phoenix version you are using - the Build ID from the About box in the Simulation rollout.

One last thing - from the Preferences box in the Simulation rollout you can browse to the Phoenix log. Right after you render and motion blur does not appear, can you grab and send the log over as well?

Thank you!

[VickyVapp]

Hello Svetlin,Thanks for the quick reply. How can I upload the 3dsMax, log and cache files ? It says invalid...

The build is: Simulated with v4.00.00, Build ID: 20191113 for 3ds Max 2018 from Nov 13 2019

[georgi.zhekov]

Hey,

Just put them into a zip file and you should be able to upload it here.

Thanks!

[VickyVapp]

The zip file is 60MB, which is more than 10MB permitted...



Do you mind if we sent it by FileMail?
Thanks.

[georgi.zhekov]

No problem at all - send it over to the support mail and we'll take a look.

Thank you!

[georgi.zhekov]

Thanks for the scene!

In the V-Ray settings, under the Camera rollout you will need to enable the Motion Blur checkbox as well, it was disabled in your scene.

[VickyVapp]

Thanks for clarifying Georgi. Yes, indeed I haven't turned on the V-Ray settings' Motion Blur. We cached two versions: a low resolution version with about 5.000.000 total cells (just to be used for previz) and another one with higher resolution totalling 75.000.000 cells for final renders. The latter is the one I gave to you.

The guy here in charge of rendering is dealing with the Final rendering. I forgot to tell him to get the HiRes cache to do the motion blur. Now it's working. So conclusion is: With low res cache, the motion blur will be indifferent no matter if we tweak in the simulator or Vray Settings.

Other two questions:

1- the motion blur default setting is set to 1.0. But if I do not want any motion blur, this will mean value of 0, right ?
2- here, I do the simulations and pass the cache result on to another guy in charge of Rendering. He will import the cache I produced in Phoenix into VRay Volume Grid for final rendering and easy manipulation. That's the time he will apply motion blur. We realised that PhoenixFDFire produces a different result in comparison with VRay Volume Grid, including obviously the motion blur look. Is this correct ? I know this is already beyond the topic in this forum, but just to show you the difference between them, I have attached an image showing how they look different (Motion blur is set to 0).

[VickyVapp]

This is the Vray Volume Grid settings to resemble the PhoenixFire settings:

[Svetlin.Nikolov]

Ah, please check this page - it contains essentials: https://docs.chaosgroup.com/pages/vi...onandRendering

In short - render settings are not stored into cache files; the caches contain only physical simulation data. You can transfer render settings by saving a preset from the Rendering rollout and then loading it into the Volume Grid.

Hope this helps!

[VickyVapp]

Oh boy. That worked ! Thank you guys ! VRayGrid and Phoenix are the same now.



No Motion Blur (value = 0)

[VickyVapp]

Motion Blur = 1 below