Author Topic: Object-Masks in Multipass  (Read 433 times)

2019-02-10, 23:21:34

Vizoom

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Hello,

Many of us render object-masks, which are absolutely essential for all the post-work!
I find the best way is to use the monochromatic black&white mask for every object-group of same materials and I´m happy that Corona-C4D offers this feature in its multipass (...with Object-ID or Material-ID).

But I really miss two things...or perhaps I just don´t know how to adjust it(?)

1.
Masks for objects behind glass!...It´s very often the case that in an exterior we have also  to tune objects inside the building, columns, stairs, furniture, people etc...but Coronas masks dont take into account that there are transparent objects in the scene (glass in windosws e.g.) and corona doesn´t generate masks for any objects behind glass...
In native C4D it worked well: The masks for all transparent objects are defined otherwise then masks for opaque objects (transparent objects appear in the masks with different shades of gray depending on their transparency) ... and we get also object-masks for all objects behind the glass ....
It seams that in coronas masks glass is seen as every other object....
So currently the only workflow to get all masks, also for objects behind glass, is to change the scene after rendering to native C4d, throw away all lights, change the material of all transparent objects to native C4d-material with transparency....and render this scene again with C4d native renderer to get the right set of object-masks...
Sometimes a little tricky because of corona-materials with alpha and of course an additional work every time!

I just spoke to another person from another studio....they have the same problem and their workflow it exactly the same I described with a second render;)....

2
When saving to a PSD-file from native C4D, all object-masks are automatically inserted in PSD-channels!..it´s great, because when you need a selection, you go to the channels, cmd-click (on a Mac) on a channel icon and you have your object selected....
When saving to PSD after a corona render, all the objects masks appear as layers, not as channels :(.....Would it be possible to cahnge it or to have the choice ;)))!

Thank you very much!!!
« Last Edit: 2019-02-10, 23:37:54 by Vizoom »
vizoom | visual craftmanship | berlin - barcelona

2019-02-11, 09:42:43
Reply #1

James Vella

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1.
Masks for objects behind glass!...It´s very often the case that in an exterior we have also  to tune objects inside the building, columns, stairs, furniture, people etc...but Coronas masks dont take into account that there are transparent objects in the scene (glass in windosws e.g.) and corona doesn´t generate masks for any objects behind glass...
In native C4D it worked well: The masks for all transparent objects are defined otherwise then masks for opaque objects (transparent objects appear in the masks with different shades of gray depending on their transparency) ... and we get also object-masks for all objects behind the glass ....
It seams that in coronas masks glass is seen as every other object....
So currently the only workflow to get all masks, also for objects behind glass, is to change the scene after rendering to native C4d, throw away all lights, change the material of all transparent objects to native C4d-material with transparency....and render this scene again with C4d native renderer to get the right set of object-masks...
Sometimes a little tricky because of corona-materials with alpha and of course an additional work every time!

Im not a C4D User, but check under the Advanced tab for your Corona material and see if you have this option (attached). Uncheck on your glass material "Visible in masks".

2019-02-11, 11:14:32
Reply #2

HFPatzi

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+1 for the second Request from my side!

2019-02-11, 17:50:38
Reply #3

Vizoom

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Im not a C4D User, but check under the Advanced tab for your Corona material and see if you have this option (attached). Uncheck on your glass material "Visible in masks".


Thanks!..I will check it...but this way I sacrify a mask for glass to get the masks for objects inside?...right?
vizoom | visual craftmanship | berlin - barcelona

2019-02-11, 18:50:10
Reply #4

James Vella

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Thanks!..I will check it...but this way I sacrify a mask for glass to get the masks for objects inside?...right?

Correct, However I use the refraction pass as a channel for glass masks.

2019-02-12, 22:59:37
Reply #5

Vizoom

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Correct, However I use the refraction pass as a channel for glass masks.

Oh, yes, this way it should work..:)....Thanks!
vizoom | visual craftmanship | berlin - barcelona

2019-02-20, 15:14:44
Reply #6

Vizoom

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Correct, However I use the refraction pass as a channel for glass masks.

Oh, yes, this way it should work..:)....Thanks!

Hmm, I tried this way, but it´s not the same: In native C4D object-passes we can put an object-ID on glass-balustrades, another ID on glass in the windows (always need to tune windowglass in post without touching the balustrades), perhaps another ID for some glass inside...for all them we get a separate channel then.
These glass objects are treated by C4D as transparent also in masks(!), so I also get the object-channels for elements behind glass (for example another glass, columns inside the building etc...)

When excluding all glass objects from masks the object-channels for opaque elements behind glass are generated, sure...
But then I miss the separate object-channels for glass-balustrades, window-glass etc....
When using refraction channel as replacement it´s impossible to separate the different glass objects placed one behind another..to have a separate channel for the balustrade and the window glass referring to the example...
So this workout will not work for us...still have to render additionally the object-passes in native C4D then :(....
« Last Edit: 2019-02-20, 15:18:48 by Vizoom »
vizoom | visual craftmanship | berlin - barcelona

2019-03-16, 11:07:46
Reply #7

8snowman8

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Please fix this "problem" because it's important to calculate one time the render with all mask.
The only way I find is to render an image first time with unflag the "Visible in mask" on glass material. At the end calculate another render with that flag active and, in corona render option, "render only masks".
In other render engine for c4d there is an option in the specular and refracion channels called "Affect Channels" if you put on "All Channels" you have all the masks.

2019-03-30, 09:16:45
Reply #8

8snowman8

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Ehi Render Legion Team, any news about the request above?