SP3 renders differently to SP2

[marek.kowalski]

Hi
After installing SP3 (or SP3a) vray renders exactly the same file very differently to SP2. Please see the attached images.
The problem happens on geometry with flipped and double faces when using irradiance map.
Sp2 didn't have any problems with that. All I had to do was to use 2 sided material and increase "secondary ray bias" to get clean render. But in SP3 the same file renders differently, with dark blocks caused by double/flipped faces.
Something changed in sp3 that causes the irradiance map to calculate differently. Is there some setting I can change to get the irradiance map in sp3 calculate the same way as in sp2? Should I do something with the material? Fixing the geometry is not really an option.
Thank you.
Marek

Ps. The images are rendered with fairly low settings. Going to high makes the problem less visible.

[marek.kowalski]

Hi Again

Is there anybody out there able to offer some kind of explanation or solution to this strange problem with SP3 that we are experiencing?
Would more detailed description of the problem help?

Thanks

Marek

[3D Betrieb]

SP1 to SP3

Hello Marek,
we got a similar problem here.
We are in jobs like mass-visualisations for catalogue and started this on SP1.
Now we bought vray rt and need to install SP3. But in a short test our reseller found out, that the results are different between this two versions.
Now we have to stay on SP1 and leave the rt on harddisk.
sad about it.
regards,
Stefan

[Paul Oblomov]

Give us an example scene... then it would be easier to find a solution...

[3D Betrieb]

Hello Paul.
The Problem is not only one specific scene, but the renderengine itself.
It is a problem if you cant get exactly the same 2 years later, cause you updated your renderengine.
If there is a solution it would be very nice...
best regards,
Stefan

[marek.kowalski]

Paul
Thanks for your offer to help. At the moment we are trying to debug the scene by ourselves. With some results.
What happens is, when we render the scene created in SP2 with SP2 the result is image 1 (see below).
When we render exactly the same file (nothing touched) in SP3 the result is image 2.
In order to get clean render in SP3 I had to merge all the stuff to a new file, then bingo! (img.3)
This is very strange for renderer to behave so differently from one service pack to the next. I can only hope we will not have to go through this process too often.
Marek

[QuakeMarine1]

save a render present of SP2 and load it to SP3
what happen ?

[Paul Oblomov]

3D Betrieb,
Hm maybe... But rendercore is being updated with new features. It rapidly evolves. I'm sure you can get the 'old-look ' in a short time

marek.kowalski,
Well me personaly can't tell you what's wrong just by looking at the pics you provided. Crop some stuff and up it here, so the whole vray community can help ya

[marek.kowalski]

QuakeMarine1
It doesn't make any diffference. Aren't current render presets saved with a file? I still tried it.

[QuakeMarine1]

settings are in the file yes - maybe sp3 translate some values incorrectly
all I can imagen is a unite scale problem or similar

so far I support sp3 noone ever reported such a problem
can you try to lower or rise the "seconday ray bias" in vray
are you using GI "from file" made in SP2 and reuse in SP3?
disable GI and compare render again

[Subburb]

Hi guys !
I've had this kind of problem (black zones in sp3) and found the way:

the "check sample visibility" option (irrad map settings) is perhaps ON. Try to uncheck it, and the black things will just disappear
Hope it helps !

[marek.kowalski]

Hi Subburb
That's exactly it! Thanks a lot for help
Marek