cryptomatte in After Effects!!

[fnordware]

Exactly the same question here. If it wasnt for ProEXR layer comps I would never know the "manifest" and "selection" part ( the "layer" is just a channel name ). Is cryptomatte designed to work only in conjunction with ProEXR?

Right, the layer name and manifest are stored in the EXR file. ProEXR uses the OpenEXR library to get them out and sets up the Cryptomatte plug-in for you. If you had them through some other method you could click on the Cryptomatte plug-in to pop up a dialog that lets you enter them manually.

Strictly speaking you don't *need* to use the ProEXR Layer Comps if you don't want to for some reason. A manifest isn't actually required and the AE plug-in will find a Cryptomatte layer even if you didn't specify one. I'd recommend it though.

[thomes]

so what exactly do i have to write in the layer field to get one special layer/material selected ? i don´t get a layer selected if i write the layername into the layerfield with < XXX >

as i understand i´m not able to get the complete layered/material cryptomatte through cryptomatte effect...

[ANIMATIK_BT]

Thx Fnordware. If i may suggest something: it would be super handy and useful if one could select layer/channel from a dropdown menu in Cryptomatte settings.
Is the manifest sort of a nodes list of currently selected channel? and how is this used in AE? It is in editable text field so it has to do something useful

[fnordware]

If you start with the bunny_CryptoMaterial.exr sample file from the Cryptomatte GitHub and run Create ProEXR Layer Comps on it, you get something like the attached screenshot. The layer name for this file is "uCryptoMaterial", and there is a manifest. When I selected the Cryptomatte effect and clicked on the bunny, it added "bunny_porcelin_matte" to the selection. If you click on the settings you'll get a dialog that lets you enter the text values manually.

If you look at the channels this file has in EXtractoR, you'll see things like uCryptoMaterial00.red, uCryptoMaterial00.green, etc. That's the pattern for channel naming that Cryptomatte uses: {layer name}##.{color}. If you don't enter a layer name, the Cryptomatte plug-in will look for a channel that fits that format, but if you had multiple Cryptomatte layers in a single EXR you would need to specify which one you wanted.

[ANIMATIK_BT]

"If you click on the settings you'll get a dialog that lets you enter the text values manually." and "but if you had multiple Cryptomatte layers in a single EXR you would need to specify which one you wanted." That is the point Why not to do this via dropdown menu with a list of available layers/channels instead of typing names Just a suggestion because I think that wolud be much more intuitive and user friendly Best regards.

[fnordware]

Thx Fnordware. If i may suggest something: it would be super handy and useful if one could select layer/channel from a dropdown menu in Cryptomatte settings.
Is the manifest sort of a nodes list of currently selected channel? and how is this used in AE? It is in editable text field so it has to do something useful

Interesting idea, but it might get a bit unwieldy because you can get thousands of objects potentially. Still might not be a bad idea to provide some sort of list. It would be work though! Are you not able to click?

The pixels in the Cryptomatte layer contain hash-coverage pairs. The coverage tells you the alpha channel for the object identified by the hash. Without a manifest, clicking in the view selects raw hashes that look like <f273a6b4>. The manifest tells you the proper name for the object that corresponds to the hash, so when you click it is able to convert from the hash to something like "bunny_porcelin_matte" instead.

You could actually enter "bunny_porcelin_matte" yourself without a manifest and the plug-in will hash it for you, but the plug-in wouldn't be able to guess that name without a manifest.

[ANIMATIK_BT]

Interesting idea, but it might get a bit unwieldy because you can get thousands of objects potentially. Still might not be a bad idea to provide some sort of list. It would be work though! Are you not able to click?

The pixels in the Cryptomatte layer contain hash-coverage pairs. The coverage tells you the alpha channel for the object identified by the hash. Without a manifest, clicking in the view selects raw hashes that look like &lt;f273a6b4&gt;. The manifest tells you the proper name for the object that corresponds to the hash, so when you click it is able to convert from the hash to something like "bunny_porcelin_matte" instead.

You could actually enter "bunny_porcelin_matte" yourself without a manifest and the plug-in will hash it for you, but the plug-in wouldn't be able to guess that name without a manifest.

To have a clear understandig, I am talking only about a Layer menu. Just a channel list to choose from. As You said it would be an overkill to have a thousands nodes list like this Please take a look at attached image.

[fnordware]

"If you click on the settings you'll get a dialog that lets you enter the text values manually." and "but if you had multiple Cryptomatte layers in a single EXR you would need to specify which one you wanted." That is the point Why not to do this via dropdown menu with a list of available layers/channels instead of typing names Just a suggestion because I think that wolud be much more intuitive and user friendly Best regards.

OK, sorry, I misread this. Yeah, it should be possible to do a dropdown for the layer. Good idea. I guess it didn't occur to me because I rely on the ProEXR for the other stuff so I don't really use that dialog too much anyway.

[ANIMATIK_BT]

That would be awesome!
All the best.

[thomes]

my AE CC 2018 version 15.0.0 shows this, no layer and no manifest shown...in selection no name, only numbers and letters .... cryptomatte V2.0 14.5.2018

[fnordware]

my AE CC 2018 version 15.0.0 shows this, no layer and no manifest shown...in selection no name, only numbers and letters .... cryptomatte V2.0 14.5.2018

Looks like you just applied the Cryptomatte plug-in to your layer. I recommend installing the ProEXR AE plug-in along with the Cryptomatte plug-in and running File > Create ProEXR Layer Comps on the footage, which will fill in extra information like the manifest.