Converting newer vray materials to earlier versions

[antony_barkworthknight]

Hi all,

I have a client who insists I use vray 2.5 with max 2014.
This means a lot of models I have downloaded have materials that do not work.
They appear blank as they will have been made in a newer version of vray.

Does anyone know a quick way to convert the newer vray materials in my scene to vray 2.5?

Antony

[^Lele^]

Besides manually scripting your converter, not really.
Why would you have to conform to a client's wishes on what something's rendered with, rather than what actually gets rendered, though?
And why on earth specifically with 2.5, which is ten years old tech?

[antony_barkworthknight]

because they inherit my models and thats the software they use

[^Lele^]

There are more things in heaven and Earth, Lele, than are dreamt of in your philosophy.

[antony_barkworthknight]

ha.
very good

[^Lele^]

Jokes aside now, would you hit me with one such model you'd need conversion for in email, so i could take a look?

[antony_barkworthknight]

Ive PMed you. let me know if you don't get it.

[^Lele^]

I PMd you back with a solution, if too late.

For the public record, the issue was with GGX on some materials.
As it didn't exist at the time of 2.5, V-Ray didn't know what to fall back to, and even too gracefully didn't complain, but rendered ghost (empty) shaders.

this line of maxscript will revert all those shaders to Blinn.

for m in ( getclassinstances vrayMtl ) where m.brdf_type == 4 do m.brdf_type = 2

Again, sorry it took me this long, but resurrecting max 2014 and v-ray 2,5, along with its licenses, proved a bit harder than expected.

[antony_barkworthknight]

Hi Lele,
This is quite a amazing thank you. It will save me so much time in the future.
I know nothing about scripting so for me it's like magic that such a short piece of text can make such a difference.
Thanks so much for your help.
The next step is to persuade my client to invest in vray 5... I wont hold my breath.

Cheers!
Antony

[^Lele^]

Eh, at least now we're covered!

For your amusement, the script says, in natural language:
Iterate over all the materials of type VRayMtl which we can collect in the scene.
If the material has a BDRF of type 4 (GGX) then change it to type 2 (Blinn).

Feel free to reuse it and experiment, there's a treasure trove of time savers one can build with a single line like the above.
Without ever needing to learn scripting properly, a few battle-lines will make your life a ton better.