Issues with RTT in V-Ray for 3ds Max

[maddin]

I am writing MAXScript code to automate Render-to-texture in 3ds Max 2018 with V-Ray Advanced 3.60.04 and am running into several issues

1.) Using non-square texture resolutions does not work when using render rendertype:#bakeSelected without a renderwidth and renderheight argument - in that case, V-Ray seems to use the resolution set in the main render dialog
Providing those arguments will not work if individual bake elements use different resolutions.

2.) Baking textures with V-Ray will directly crash 3ds max if a non-V-Ray bake element is used (e.g. the normal CompleteMap element).

3.) When using RTT with V-Ray Framebuffer enabled, I get a warning that my textures will be lost - but they show up just fine?

All these issues do not exist when using the old Scanline renderer.

Any ideas or comments on any of the above?

Thanks!

[tashko.zashev]

Hi,

Not sure what is the correct behavior for the point one. Have you tried with Scanline? Does it work in a different way ?

Point 2) You have to use only the listed V-Ray baking elements, the unsupported Max native ones will make the RTT to crash in most cases.

Point 3) it's because the RTT uses the Max output with our VFB, but the result will be saved though.

Hope this helps!

[maddin]

1.) Yes, Scanline works just fine with this setup (of course I need to change the bake element from the V-Ray specific ones to those compatible with Scanline).

2.) I would expect V-Ray to produce an error but a crash...?

3.) Not sure I understand - will the output be OK or not if the V-Ray Framebuffer is enabled? The warning suggest it will not, but the files look ok

I will try to attach a zip file to this post that demonstrates the issues. Just open the .max file and run the MAXScript code. This will produce 3 bitmaps (when it only should produce 2), all at incorrect sizes (and I am not sure the lighting map is correct?).
See the MAXScript file for some more information.

[tashko.zashev]

Thank you for the files first. This is really helpful most of the times for troubleshooting issues.
I will try to summarize and provide an answer to all the issues you have found related to the RTT and V-Ray below.

1) There is actually an issue with the non-square baking process and it seems to be already in our bug tracker. It's issue VMAX-991. I'll see if we can bump its priority a bit.
2) It is definitely not good for the baking to lead to a crash with unsupported baking elements, but this seems to be a not easy fix. We have a bug submission about this in VMAX-7386. So hope we will have a warning instead of a crash in one of the next releases.
3) I'll discuss those warnings with our developers. Even if the message in the log says "VFB is enabled.... - baked elements will be lost" the baked result will be saved to the location specified in the RTT field. If they need to be reworked we will do that.

It looks like V-Ray 3.x doesn't respect the Enable check box in the selected baking element. This seems to be fixed for V-Ray Next. Will see if we can get this fix into the 3.x builds. VMAX-4984

Don't see any problems with the lighting map with this setup. Can you give me more details?

[maddin]

Don't see any problems with the lighting map with this setup. Can you give me more details?

I was expecting the lighting map to contain only lighting information, not the base color of the object, but maybe I am mistaken?

[tashko.zashev]

I was expecting the lighting map to contain only lighting information, not the base color of the object, but maybe I am mistaken?

I guess you need the VrayRawLightingMap in this case. The Lighting element contains the data from the Raw light and Diffuse.
You can find how each element contributes to the Beauty here https://docs.chaosgroup.com/display/VRAY4MAX/RGB_Color