What's the proper workflow for alpha? PRE VRAY USER Tweet

[BLKRCAT]

So I'm coming from Vray for c4d. My workflow from there was always to render out flat linear EXR files as well as 16bit PNGs for my various passes. Multimattes can be set using Vray Tags and an objectID can be set within the tags. Choosing the mattes to render is very similar to how c4d uses its object buffer system.

Coming into Octane the last week and Im looking to see if the workflow is the same or not. I've watched a few tutorials out there and read the manual but there isnt much information out there on rendering out straight alpha passes other than using "straight alpha" in the c4d render output rather than using the octane one, the only disadvantage to this is that the alpha then is also 32bit EXR as well.

I've played with some passes and I'm not sure im setting things up correctly but it looks like the info pass from the ObjID doesnt respect any camera blur or motion blur settings. Neither does the Layer Mask option.

Is there a way to render out straight black and white alphas as 16bit pngs along with my 32bit beauty that match up with any motion blur or DOF that I add into the final render?

[bepeg4d]

Hi BLKRCAT,
look at the attached image:

here is the link at the Standalone documentation about info passes:
https://docs.otoy.com/manuals/products/ ... fo-passes/
ciao beppe

[BLKRCAT]

thanks bepeg4d, i'll check it out. Looks like its going to do the trick for me.

[BLKRCAT]

I'm actually still noticing the edges not being perfect even with Distributed ray tracing enabled in the info passes tab. Actually, I believe it was on the whole time because it appears its on by default. I did some tests with the tonemapping type as well but it didnt seem to make a difference.

I'll upload the temp project im experimenting in, perhaps someone can point me in the right direction? I haven't had to use the feature yet, I just know I will sometime in the future.

[bepeg4d]

Hi BLKRCAT,
please look at the attached scene, I have removed the Render layer mask, and acrtivated the Object Layer Color pass in the InfoChannel section. With a Object Tag, it is possible to define the desired color for each part that needs a specific mask.
I have also increased the sampling in the info channel section at 1024, with DOF it is necessary to cook a bit more, in general.

TempProject_b.c4d.zip

(710.78 KiB) Downloaded 301 times

Happy rendering,
ciao beppe

[BLKRCAT]

Ah! thank you for this help!! I downloaded your project and I've got it all figured out now. (I think at least, going to try on a new project over the weekend hopefully.)

It's strange that the default object layer color is black, and that it would be set in the object manager. I didn't expect that at all. Interesting in that I could see benefits to using this for RGB multipass perhaps. Is there any specific reason you switched the main object to ObjID 2?

But I did notice that my object ID passes were consistently black. Makes sense that they were initially black on black.

[bepeg4d]

Hi BLKRCAT,
by default, everything in the scene is in the Object layer 1, so in general, if you want to isolate an object, you assign an Octane Object tag with an object layer greater than 1.
Happy rendering,
ciao beppe