AOV Tutorial? BW mask for object Tweet

[ceen]

Hi,

I am trying to render a bw mask for an object with the new AOV system. I fail to see how to output the render layer ID from the object tag as a black and white pass. Is there a way? I only get colored RGB passes?
OctaneRender Studio 2020.2.3

(AOV groups crash C4D every 3 minutes here)

[speltrong]

You can use the Render Layer Mask system for this, though you really should start learning the Cryptomatte system (colored masks) going forward since it's so much better. I'm in the middle of writing up a full guide on this, but this should get you through:

Simplest workflow for a Render Layer Mask:

Add an octane object tag to your geometry. In the Object Layer tab, set the Layer ID to anything other than 1. 1 will merge in with the background, so start with 2 or 10 or whatever.

In C4D Settings>Octane Renderer>Render Passes tab, check the Enable checkbox at the top. Put in a file name. Use EXR format (NOT EXR(Octane)). EXR(Octane) will work well with Cryptomatte, but not Render Layer Mask. At the bottom, there's a section for Render Layer Mask - twirl that down and check ID 2 or whatever you used.

Also check Save Beauty so you get the beauty pass in the same file.

Keep in mind that Render Layer masks take an excessively long time to produce and can even multiply your render time per frame if you have several of them.

A better way is to do the same steps above, choosing a Layer ID that's not 1, and then choose EXR(Octane) from the format. Go to the Cryptomatte section instead of Render Layer Mask and check Crypto Object Node (this sorts the colors based on the Layer IDs you choose). Then use your post application to extract the correct mask. In Photoshop, you'll want the exr.io plugin (free), and tell it to extract cryptomattes. For Ae, you'd use EXtractoR which has the ability to pull specific masks based on what you chose.

Cryptomatte is much, MUCH faster than Render Layer Mask and accounts for things like depth of field and motion blur nicely.

hope that helps

-s

[bepeg4d]

Please avoid to use the old Render Masks, they ar deprecated.
Old Render Masks are not good, since are calculated by c4d internal render, so they cannot consider DOF or Motion Blur, and can only offer a brutal b&w mask of the geometry.
They were added in c4doctane plugin when Octane SDK did not have any pass related to Layer ID.
Not only, they are not supported in Standalone or ORC/RNDR.

Cryptomatte is great, but sometimes it is even too much, if you need only few masks.
In this case, you can use the Object layer color pass, and define the color of the Object pass with an Octane Object tag:

ciao Beppe

[speltrong]

That's good to know - going to add that to the guide

Thanks @bepeg4d

[SSmolak]

I think that every old features, nodes, materials, settings should be marked with different color or font because there too many old features that are not supported anymore and they exist only for compatibility reasons.

[NVN]

Do I understand this correctly?
You can only render multiple b/w images with Cryptomatte?
The type "Render layer mask" in the AOV is therefore totally useless?

I personally find this really sad.
Cryptomatte is quite nice, but something like this has to work natively....other renderers can do it too.