Using Cryptomattes in Blender 2.8 - Compositing Tutorial 

* whispering * *CGMATTER*

It's not quite that, I think. This is just compositing. The way they showed it here, reflections of the object, say, won't change color along with said object. Although you can kinda do that with various render passes.

@@Kram1032 , yes, just after I posted this and thought about it again, I realized that. Nevertheless, impressive information. Thanks for the answer.

Sort of but not a show/hide layer, Crytomattes store a mask of everything "automatically" and save it in the image file. This becomes even more powerful with animation when you realise that a motion blurred blue object that zips behind other objects in the animation needs to be red, with a Cryptomatte pass included in the image file you can fix that in post production almost instantly rather than thinking about re-rendering that object and comping it over your master edit. The difference between layers and Crytomattes is that it is a ready setup selection Mask for every Object and Material in your rendered image and the software you use needs to allow you to "Pick" the matte out of the image using the picker tool, as they showed here in Blender's compositor. Most major software has Cryptomatte support in it these days.

Thanks Dan! Blender is a very exciting tool and 2.8 makes it much better. We dont believe it's becoming industry standard anytime soon, but it's still a great tool to know for freelancers or hobbyists.

Ahh I see - cheers guys 👍

I can think of a couple of reasons: 1) Blender has the most helpful community 2) Most users of the proprietary apps only have cheap personal/non-commercial licences, so they can’t put work on commercial sites like RU-vid.

a bit late, but select the ground object, go to theobject settings and enable "shadow catcher" under the visibility settings

Yes you could export it at render time

They’re saved in the EXR files, right?

@@ciaranpmryan That's what I'm not sure about either. I have no idea how cryptomattes can be stored since it's not pixel data.

Benjamin B. As long as you render and save your EXR file, it should be in there. From the main output I render as EXRMultilayer, that way I have everything in the compositor, do what I need to do there, and then have a PNG sequence output from there. It renders two file sequences, but you can then go back to the EXR files and change stuff there if needed without rerendering.

Darren New The data is stored in the EXR’s. Once you render out and save an EXR, the mattes are also saved.

you can do both. Like if you wanted add force field effect to entire character, use asset, and then add more reflection to cloth, use material or object.

You can, but you'll need plugins to read the cryptomatte data correctly

check out EXR-IO, free plugin which does exactly that (render passes and cryptomatte layers to photoshop) you just have to save render as exr multilayer. Then in PS you can just CTRL+Click to select masks. They have tutorials on how to assemble back the final image from the passes, I'm just checking those out atm

Andrew Price recently said to use Mist and limits with the camera instead because Z-depth pass has horrible harsh edges.

@@TheCobyRandal has it been reported to blender? getting a z pass shouldn't be this difficult!!

@@jkartz92 it's not difficult, use Mist pass with the distance options in the camera settings. Z deph usualy looks just white, because its saves the distance values and white is reached by only one unit distance, so you need to set the ditance values by using a Map Range node. So just different ways to set the maximum and minimum values and Mist has antaliasing, zdepth not, because you sometimes dont want that.

Lo Hung Wang yup, Cycles only for now 😢

No, this is pure post processing. Its like taking the renders into Photoshop.

Try to decimate your models in ZBrush first to reduce the polycount.

Thanks

We'll keep this in mind, thanks!

Upcoming tutorial for us 👍

FlippedNormals thankyou so much

Yes, Nuke definitely has a more elegant Node system.

What matters is what you can make with them.

Yes! More will come.

Yeah, because I still don't like it.