/3/ - 3DCG

[Anonymous No.783519]

Are cryptomattes really a game changer like flipped normals says? Should i be using them?

[Anonymous No.783530]

>>783519
>game changer
overused marketing buzzword

Do you need them in your compositing workflow? Then do so and don't ask like a dumbfuck.

[Anonymous No.783554]

>>783530
do (((you))) use cryptomattes?

[Anonymous No.783556]

>>783554
I haven't done any compositing that would require it. It's simply not my field.

[Anonymous No.783569]

>>783519
wtf is a cryptomatte.

[Anonymous No.783570]

>>783519
it's a glorified clown pass or matid or whatever it's called. But yeah, If Blender has it, you should use it if only for the fact that it generates the masks automatically and saves you time. But overall it's really not such a big deal

[Anonymous No.783574]

>>783519
It's not a "gamechanger" but damn if it isn't useful as fuck. I only wish that eevee supported them. And that the mattes actually worked with shit like depth of field. But the dof thing doesn't really seem possible because of what the mattes actually are.

[Anonymous No.783582]

>>783570
>clown pass
Fuck, that fits. I need to introduce that terminology to my colleagues .

[Anonymous No.783588]

>>783519
I only use blender to sculpt/modeling shit to 3d print
>Are cryptomattes really a game changer
Not to me

[Anonymous No.783591]

>>783570
>clown pass
Is that when Bozo grabs your ass?

[Anonymous No.783595]

>>783591
>Ronald McFondled

[Anonymous No.783597]

>>783591
>>783582
Do a Google search, it's not really a new term or unheard of. But I think Keyshot is the one who popularized it

[Anonymous No.783652]

>>783574
Eevee cryptomatte is on its way

[Anonymous No.783668]

>>783570
>But overall it's really not such a big deal
>>783574
>It's not a "gamechanger".
It is a big deal and kind of a gamechanger, but not really for us 3D artists, but for people who do compositing.
In terms of ease of use, quality and efficiency this feature gives a lot of power and makes the work a lot faster. So yeah, its a HUGE fucking improvement in comparison to how the workflow looked before.
>>783574
>And that the mattes actually worked with shit like depth of field. But the dof thing doesn't really seem possible because of what the mattes actually are.
I never have tested the Blender version of Cryptomatte, but in fact it should support DOF and motion blur (that's kind of the point), it does in Arnold and Clarisse.

[Anonymous No.783697]

but bros, how can this cryptomatte business posibly work with GI? You change one area, the rest doesnt magically re-trace to compensate for that change

[Anonymous No.783717]

>>783697
Its true that you can easily destroy the energy conversation of the GI so you just don't do it.
You change the colour of something not the light intensity.

[Anonymous No.783732]

>>783717
you have a blue ball sitting on a metallic, reflective ground plane. when you change the balls color using cryptomatte from blue to red the resulting image isnt correct, physically. What am i missing here?

[Anonymous No.783735]

>>783732
You're supposed to render all those other render passes and "reconstruct the shader" in whatever compositing software you use. Then you can use those to change the gi.

[Anonymous No.783747]

>>783668
No, it's not a gamechanger. It's just adopting a workflow that's been standard for years. Blender is behind the curve. Don't get me wrong, I love the cryptomattes, but all it does is make the process of masking a bit quicker. You could do effectively the same thing using scene layers or material passes.

Blender's doesn't support DOF or blur. I'm not sure why it should either. Since that means that other objects will be part of the selection when changing things, or you'd get a halo around whatever you're selecting. Though I don't know how it works in other softwares. Really I just wish the mattes were aliased.

>>783652
Neat. That'll come in handy.

[Anonymous No.783748]

>>783735
if my compositor is blender, how would i do this? wouldnt it be better to stay in one package? flipped normals didnt really get into this

if my compositor is nuke, how would i do this? wouldnt the experience be worse since you have to export everything from blender to nuke?

[Anonymous No.783757]

>>783748
>if my compositor is blender, how would I do this?
No idea, haven't used blender in years and even when I was using it I wasn't using the compositor
>>783748
>wouldnt it be better to stay in one package?
It would, ideally, but for professional work each step of the pipeline has a dedicated, specialized software that it's the best. If you can get out of Blender to use Substance Painter, you can do the same for a a compositing software
>if my compositor is nuke, how would I do this? wouldnt the experience be worse since you have to export everything from blender to nuke?
Don't know about your experience, but what you do is render everything as openexr with multilayer feature enabled and then you drag and drop it into Nuke. Then you connect everything up to reconstruct the shader and using grading nodes you can pretty much change everything

[Anonymous No.783761]

>>783757
Yeah, but still, with what render pass can you change GI only around the colored object you just changed? I guess you'd have an object render pass for a particular object and you change it e.g. from blue to red with color grading, right?

But how do you change the bounced color from it? With what pass? Is there a pass which only renders indirect lighting from a particular object? Otherwise I don't get how I could color grade only that particular area, if it's animated. Without masking by hand or something like that ofc.

I get it you can reconstruct it and change general things like direct, indirect light, roughness etc. across the whole shot, but what about only a small area?

[Anonymous No.783776]

>>783757
> Then you connect everything up to reconstruct the shader and using grading nodes you can pretty much change everything
What "shader"? I have a principled shader graph

[Anonymous No.783805]

I just thought of this workflow...bear with me:

>render once with crypto enabled
>use crypto to adjust colors
>done with overall look
>re-render with adjusted settings in real material and now have secondary rays be correct

is this optimal?

[Anonymous No.783808]

>>783761
>with what render pass can you change GI only around the colored object you just changed
The GI pass
>But how do you change the bounced color from it?
Not sure how you do that in Blender but in Nuke you could just use a Keyer node attached to the GI pass to isolate the area around the object. First you grade the GI pass to make the individual areas distinct, then you use a keyer to create a mask only on the area where you want to change the color, then you use this mask to grade the original GI pass.
I'm sure there are also other methods, probably even better than this one.
You can also create different render layers for each object and then merge them together at the end, thus giving you freedom

[Anonymous No.783813]

cryptomatte doesnt generate IDs for volume shaders - you cant pick them. What is a workaround?

[Anonymous No.783826]

Can you fix other stuff in post without having to rerender, e.g. animation on objects or simulations? That's the real problem for me, and realtime engines help a lot because it's super easy to change and rerender. With offline renderers I feel like I'm fucked if anthing goes wrong and I don't notice it until the shot is rendered. The best option I know of is to use render layers so at least you only need to render a particular object, but that's still a pain.

[Anonymous No.783852]

>>783813
Material ID.

[Anonymous No.783911]

>>783852
Unfortunately, I can only get Material ID to work on regular objects, not volumes. I have a scene with one large sphere, two small spheres, and a smoke domain / emitter. It doesnt make a difference if the emitter is hidden or not since the sim is already cached

On the material I set the pass index to something other than 0 then I enable object / material passes in view layer properties. For a test I set both the large sphere and the flames to the same material pass index, 3, saying that they should both be visible when i solo them with the viewer. Only the sphere turns white.

I repeat the test, this time with object ID, setting object properties->relations-passIndex to 3, re-rendering, setting up the objectID indexOB node with the mask and soloing it. Same result.

Seems like volumes are unsupported for cryptomatte and material id and object id. Am I messing up somewhere?

[Anonymous No.784351]

>>783911
any help with this?

[Anonymous No.784360]

>>783911
Vray creates a matid for those things when you add an atmosphere+selfilumination pass. If that doesn't work, just render it solo on a separate layer with a transparent background
If that doesn't work either ask the blender devs

[Anonymous No.784484]

>>784360
>vray
we're talking about cryptomatte in blender, which is only for c y c l e s

[Anonymous No.784498]

>>784484
No, we are talking about cryptomatte which is available for many renderers and has been for many years.
The fact that you are trapped with cycles and its suboptimal implementation is your fault and yours alone.

[Anonymous No.784499]

>>784498
this is a blender thread, flipped normals were only using blender in their video

[Anonymous No.784501]

>>784499
Cry harder little piggy.

[Anonymous No.784509]

>>784484
>only for c y c l e s
Pathetic.

[Anonymous No.784528]

>>784509
>>784484
>only for c y c l e s
For now anyway.
If the Eevee compositing passes are anything to go by, Evee cryptos are probably just around the corner.

Really, I just want the ability to put screenspace effects like bloom onto cycles renders natively. It's such a hassle to render a scene in both engines to comp the bloom from eevee on top of cycles. And doing the bloom manually with the glare node in comp is pretty shit and doesn't produce a similar result.