how to use clown passes in after effects

[PerFotoVDB]

Hi guys,

I need some help in using clown passes to make selections/mattes of parts in after effects.
Looks like I need to key the clown color and convert to an alpha or track matte. I am not sure, I don't use AE often.
(cryptomatte in KS would be a great addition;) )

Does anyone know how to do that?

Many thanks,
Per

[froggeryz]

The few times I have done this I just applied a flat white material for the parts I needed and flat black for the rest and then just rendered the sequence again.

[Esben Oxholm]

The few times I have done this I just applied a flat white material for the parts I needed and flat black for the rest and then just rendered the sequence again.

That's what I do as well and make sure to render it using the custom control for better AA.
I struggle to get clean edges on the selection when trying to key the clown pass.

[PerFotoVDB]

Thanks guys,

I did the same. Applied a flat black material to all parts except the one I am rendering new again, this way I have proper occlusion.
Unfortunately, the alpha in the exr still takes the geo with the flat black into account. I want the flat black material not be picked up by the alpha.
Would be awesome to have some more control over this. Either on an object level or on a material level.
That's why I needed to output the clown, to make a selection and mask.

To bad KS lacks some proper composting support.

Do you guys have any workaround?

Thanks, P

[PerFotoVDB]

@Esben: overall I feel the custom control is the best way to render because of the better AA control.
Still looking for optimal settings in 4K animations on network nodes.

[Esben Oxholm]

To mask out the re-renderet part you would need to create an additional output of a pure black and white mask: Flat black on all parts except the one you've rendered again. Flat white on the re-renderet part. No alpha on this one.

Output and use that black and white mask sequence as a luma track matte for the original re-renderet part.
That should give you the re-renderet part on a transparent background.
Does it make sense?

Would indeed be great to be able to render selected objects only on a transparent background with proper masking.

[PerFotoVDB]

True! Why didn't I think of that?

I used now keylight to key the yellow color in the clown pass and used that as a mask in AE.

Will give your method a go as well. I expect to have fewer edge issues.

Thanks!

[andy.engelkemier]

http://tepavicharov.com/?p=25

This. This should be the inspiration for clown masks in keyshot.

Ok, it's has WAY more features than it used it. But give the video a watch. The main takeaways there are, select object, render out luminance map. So you can Immediately use it in after effects, Or have better selections in photoshop, without extra steps.
OR, you can choose to render object ID. It Randomly assigns colors to every single object. Or material ID. It's Not based on the material color, so if you have 5 black objects they don't look the same!!!
I sent him a message back in like 2010 and he changed that method to not include desaturated colors. I think it now uses the same color output by using the same order, RGBCMY - then divide between those, once or twice, then cut the value in half, and do the same thing. Anyway, the order always ends up being the same and the colors are always as far apart as possible. None of this purple next to magenta garbage.

And if you want to Really wow some folks. Give a way to select an object(s), then render the selection Including transparent objects, and all reflections with the only objects allowed reflection to be your object, where all the colors are changed to black. That way your object is selected everywhere it's seen. This takes Way too long to set up manually. It also doesn't work if the object is reflected in another object, and that object's reflection is reflected in another object clearly. But that is pretty darn rare that it's noticeable past the first reflection. (I say that, but it happened to me yesterday)

Good selections save So much time in post.

[Eugen Fetsch]

How about implementing Cryptomatte (Introduction, on github) like other render engines? That would save a ton of time in compositing.

KeyShot is not focusing on animation or VFX production, that's why we're missing such features. Otherwise we would already have ...
- Camera animation export for FBX
- Multilayer EXR support for render output
- Diffuse & reflection indirect passes
- UV pass, for texture replacement in post
- Object ID pass
- Vector pass, for adding motion blur in post
- etc.

[Esben Oxholm]

Would indeed be very nice to have cryptomatte, camera fbx export, vector pass, etc...

[Eugen Fetsch]

Would indeed be very nice to have cryptomatte, camera fbx export, vector pass, etc...

I would cry happy tears if only fbx camera export would be available and howl like



seeing all the rest.

Imagine that easy life, adding tracked motion graphics in your renderings or saving hours of rendertimes with vecotor motion blur.

A studio asked me once for a camera export and I was like: "sorry it's not available in KS" 

The only workflow I could find, is to put checker texture materials on everything in the szene, render it with 8 samples in prieview mode and track it manually in post. If somebody knows anything better then this, I would highly appreciate to see it.   

[DriesV]

Hey guys,

Just letting you know that we are logging these requests and keeping track of them.
I can't give promises on development though. As some have correctly noted, VFX is not our main focus, and that is indeed why some of these features haven't made it in KeyShot yet.

Dries

[andy.engelkemier]

Would it help to know every post I've made in the last two weeks was Only related to renderings I'm doing for packaging?

Not vfx or animation. Things like object I'd can still be a huge time saver.

Should we post what the request is for more specifically?
The reason I'm using keyshot is primarily because the clients Also use keyshot.

[Esben Oxholm]

Just letting you know that we are logging these requests and keeping track of them.
I can't give promises on development though. As some have correctly noted, VFX is not our main focus, and that is indeed why some of these features haven't made it in KeyShot yet.

Hi Dries.
Thanks, good to know. I'll second Andy here. Don't need it for crazy vfx stuff. Would be quite helpful to have for basic product animations as well

[DriesV]

Yes, more details help. Or showing why the current tools are a pain, and other solutions would not be.

Dries