Author Topic: Corona VDB 7 vs 6  (Read 365 times)

2021-09-02, 22:18:57

olivierc

  • Users
  • *
  • Posts: 4
    • View Profile
Hello,

When you render a vdb file in Corona 6 which looks fine, the same file in Corona 7 hotfix 1 gives a completely different result. The VDB is almost transparent..
I have tried with a completly new scene, new load from a VDB file, I confirm, it is not working the same way as before.

Max 2021.

best,
Oliver

2021-09-02, 22:35:54
Reply #1

olivierc

  • Users
  • *
  • Posts: 4
    • View Profile
Ok, I think I found the problem. Scale seems to be the problem between Corona 7 and 6.

If the CoronaVolumeGrid object is not scaled in Max, there is no problems. The VDB seems to render correctly.

But if there is a scale on the CoronaVolumeGrid object, in my case, 2%, then the VDB renders almost transparent. Step size seems to change but is far to solve the problem.

Whereas this issu with the scale was supported in Corona 6.

Please can you have a look at this bug ?
What would be the workarround ?

Thank you !

Olivier

2021-09-06, 10:35:09
Reply #2

rowmanns

  • Corona Team
  • Active Users
  • ****
  • Posts: 1303
    • View Profile
Hi,

Please can you provide a scene?

Thanks,

Rowan
Please read this before reporting bugs:
How to report issues to us!

2021-09-06, 10:55:02
Reply #3

v.p.vlasenko

  • Active Users
  • **
  • Posts: 49
    • View Profile
I confirm this problem, noticed that some time ago.

2021-09-07, 11:07:35
Reply #4

rowmanns

  • Corona Team
  • Active Users
  • ****
  • Posts: 1303
    • View Profile
Hi Guys,

Please can you send me one of your affected VDB files? I just tried this here and it seems to work fine for me, so maybe there is something which I am missing.

Thanks,

Rowan
Please read this before reporting bugs:
How to report issues to us!

2021-09-08, 16:32:30
Reply #5

olivierc

  • Users
  • *
  • Posts: 4
    • View Profile
Dear Rowan,

Thank you for your reply.

smoke on the left is 100% and smoke on the right is 1,4%

smoke" border="0

The max scene is attached.

Best,
Olivier

2021-09-14, 13:38:41
Reply #6

v.p.vlasenko

  • Active Users
  • **
  • Posts: 49
    • View Profile
Hi people,

seems like vdb is broken more than I thought or even volumes at all.

empty scene, scale in meters, sun size 5 (with default size same thing), default environment and "wdas_cloud_quarter" - step 1m

First of all, even with a 100% scale it does not work as expected
first attachment - 100%, we can see the sun through volume and I checked it with phoenixfd - similar result, so that not only coronavdb problem.
second - 5% scale.
third one - 5% scale, but step 0.2m.
fourth - 5%, step 5m.

Decreasing step size doing things even worse

I tried different absorption, scattering constant/density with different multiplier - all wrong.
So definitely something broken.

Btw it seems like phoenixfd producing correct? results at all scales - but in all cases we can see the sun through cloud.


2021-09-14, 13:55:39
Reply #7

olivierc

  • Users
  • *
  • Posts: 4
    • View Profile
Hello,

Thank you. Yes I experience the same problem. Clouds have a strange "cut out" effect in its volume.

In Corona 6, scale was definitely not an issue.

Best,
Olivier

2021-09-15, 10:54:10
Reply #8

rowmanns

  • Corona Team
  • Active Users
  • ****
  • Posts: 1303
    • View Profile
Hi,

Thanks for the scenes, we have managed to reproduce this here.

We will let you know when there is some more information.

Thanks,

Rowan

(Report ID=CRMAX-968)
Please read this before reporting bugs:
How to report issues to us!