OSL -> standalone export: wrong render result

[racoonart]

Hi,
I have a problem with exporting my max 2020 osl shaders (native, not the vrayOSL texture). It renders fine in max - shows a light/dark gray checker pattern on the Teapot. However, when I export to .vrscene and render it with standalone (both max and the separately downloadable) it just renders a gray teapot. I don't get a warning or error.
Some OSL shaders like the OSL:Checker map that ships with max renders fine, my own one however doesn't. So it probably is some minor thing somewhere that the max osl compiler and the vray osl compiler interpret differently. I just have no idea how to find out what it is.

A file for testing is attached. Thanks for any help!

[vlado]

Thanks for the scene; looking into it.

Best regards,
Vlado

[racoonart]

Looks like this is not the only osl shader that doesn't render properly. Let me know if you need more examples (I would prefer to upload them in a private place however).

[Edit] Oh and if you have any idea if it's going to be fixable or not, please let me know, I'm currently at the point in the project where I have to decide if I need to drop osl and redo everything without it or if there's a chance it could be fixed and work within a few weeks.

[vlado]

Afaik a fix is ready and will go into the nightly builds in the next few days.

Best regards,
Vlado

[racoonart]

Awesome! Thanks! I'll better send a mail to support for the vray standalone nightlies access then

[vlado]

This is fixed in the nightly builds for V-Ray for 3ds Max and V-Ray Standalone, and will go into the stable_4.2 builds tomorrow.

Best regards,
Vlado

[racoonart]

I just tried the new builds and this particular bug seems to be fixed, thanks a bunch!
However, now there are other (though more subtle) differences between the render in vray4max and in Standalone. I'd like to send you the scene for a closer look and debugging but I can't upload it here publicly.

See the attached image. Left is vray4max, right is standalone.
1) the overall look of the dirt streaks is vastly different, best seen under the upper row of windows
2) the bump map strength is a lot higher in standalone

There could be more but these are the most obvious differences I have found so far.

[racoonart]

Ok, I took apart the shaders and boiled it down to a small shader tree that I can upload. It shows both the color difference and the bump issue. The first is caused by the "channelComp" node (which is a slightly modified version of the original osl composite).

Attached image shows max on the left and standalone on the right (using the fixed builds from yesterday).

[vlado]

Thanks a lot for the scene, looking into it!

Best regards,
Vlado

[racoonart]

One more note: I got rid of the VrayColor2bump nodes and the bump strength is still much higher in standalone. I would prefer the standalone version actually, because I really need to crank up the bump map multiplier in max to even see anything at all (500-1000). Not sure if this is possible for compatibility reasons but it is still a bit of an issue.
[Edit] Multiplying the map itself faaaar into white also works, so... nevermind

[racoonart]

Any news on this?
Really don't want to appear impatient but a current project is dependent on this OSL stuff and I'm running out of time soon.

[houourin]

I was struggling with trying Vray to show something on the BUMP channel with OSL maps ( noise ) in this case. Couldn't see anything at all.
Then I found this thread, and apply 1000 to the bump. and voailà! appeard.

Is this suposed to work like this?
OSL materials start to get fancy in Max could be nice to have a good compatibility with Vray.

[racoonart]

It's not supposed to be normal but if I remember correctly, fixing it appeared to be a bigger issue that takes some time to fix. My last information about it was that it is being worked on.