Forums » CentiLeo for Cinema 4D
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No exclude function in rendering?
 
LU
User  Posts: 9
Sep 14, 2021 02:45
In some cases, I need to exclude something to make alpha channel for them(but not disable them, they are still functional for rendering purposes , unlikely I can't find a way to make this happen. If there is a command like c4d Compositing tag that you can disable anything you don't want, that would be very handy.

object ID doesn't function, and there is a bug for it, when you assign it, there is nothing (no tag)appear in object manager, so that this way is cut.
 
Administrator  Posts: 593
Sep 14, 2021 06:51
Hi LU! So you want to exclude an object from alpha channel image but not from beauty image using an object tag?
Actually there is no currently such functionality, but exclusion system and lighting / shadow excludes/includes are planned. I know how to do them now in genereal and collect user experiences. They can be implemented in a different way. I would appreciate if you would advise the most convenient examples.
 
LU
User  Posts: 9
Sep 15, 2021 10:10
What I mean is that when you render some translucency or transparent object, you need to keep other things on, like to keep back stage on , or other related objects on, so that the transparent effects will look correct (because transparent/ translucency will be impacted by environment and other surrounded objects). But sometimes I want to keep the transparent objects with the same look, just need to change background , so that I need alpha channel for them. The problems is, there is no alpha channel for this scenario. See the picture

in this scene, I want to keep that look above, but that doesn't have alpha channel for the small objects; while, when I turned off the back stage object, it does have alpha channel for the small objects, however, the look for them are different. I want to keep above look, don't turn off back stage, and still have alpha channel for small object.

in C4D native renderer, it has a tag called Compositing, you just apply this tag and click off "Seen by Camera", this could be achieved instantly. see picture below;
 
Administrator  Posts: 593
Sep 16, 2021 13:34
Thanks LU! More or less I understand this. I will test Composite tag more to do something like this.
 
I would also like this feature.
with 3delight I am able to use the composite tag to have my ground object plane invisible to the camera but still give reflections to objects on top of it.
This is very useful for making the ground render as alpha so I can composite objects into after effects.
I hope this feature is available now or soon, or it is a deal breaker for me to switch to this engine.
I'm looking forward to starting to use this centileo.

Also, I need to be able to catch shadows on the same ground plane and render out a shadow pass. Is this possible?
Edited: ssjenforcer - Oct 21, 2021 22:02
 
Administrator  Posts: 593
Oct 21, 2021 22:44
Quote
ssjenforcer wrote:
I would also like this feature.
with 3delight I am able to use the composite tag to have my ground object plane invisible to the camera but still give reflections to objects on top of it.
This is very useful for making the ground render as alpha so I can composite objects into after effects.
I hope this feature is available now or soon, or it is a deal breaker for me to switch to this engine.
I'm looking forward to starting to use this centileo.

Also, I need to be able to catch shadows on the same ground plane and render out a shadow pass. Is this possible?
It seems all you want is possible right now. Just make a ground plane, drop a material with "Matte / Shadow Catcher" option On. Swich on Alpha Channel AOV - and it will render shadows on the plane, but will not show the plane in alpha channel. Also you can use Sphere (Omni) light sources or HDRI Sky with Shadow Cacher intensity to change the strength of shadows casted on matte/shadow cacher object
 
Quote
Kirgman wrote:
Quote
ssjenforcer wrote:
I would also like this feature.
with 3delight I am able to use the composite tag to have my ground object plane invisible to the camera but still give reflections to objects on top of it.
This is very useful for making the ground render as alpha so I can composite objects into after effects.
I hope this feature is available now or soon, or it is a deal breaker for me to switch to this engine.
I'm looking forward to starting to use this centileo.

Also, I need to be able to catch shadows on the same ground plane and render out a shadow pass. Is this possible?
It seems all you want is possible right now. Just make a ground plane, drop a material with "Matte / Shadow Catcher" option On. Swich on Alpha Channel AOV - and it will render shadows on the plane, but will not show the plane in alpha channel. Also you can use Sphere (Omni) light sources or HDRI Sky with Shadow Cacher intensity to change the strength of shadows casted on matte/shadow cacher object
How do I render objects with a transparent background so I can composite them into After Effects?
I tried with one and it had a white background but it wasn't transparent. Then I tried checking the 'transparent background' render option under render settings-->centileo-->AOVs/passes, and that gave me a black background but not transparent either.
I tried also checking 'alpha channel' and that did not help.

EDIT:
I checked 'alpha channel' under render settings-->save and that seems to work.
Do I still need transparent background and alpha channel checked in the AOVs/passes section as well to make it all work?
Edited: ssjenforcer - Nov 9, 2021 22:16
 
Administrator  Posts: 593
Nov 10, 2021 00:29
"transparent background" option will replace the background of image (area without objects) with a greyscale checkerboard pattern. This means that in place of checkeboard pattern you will get transparency if rendered image is saved with "png" or some other image format that supports transparency. This is also possible to project the semi-transparent shadows casted on a transparent background.
This has nothing to do with "alpha channel" flag in AOVs render settings. This alpha channel flag adds an additional black/white image pass to the main beauty pass. Alpha channel shows the white mask of objects on a black background.
 
Quote
Kirgman wrote:
Quote
ssjenforcer wrote:
I would also like this feature.
with 3delight I am able to use the composite tag to have my ground object plane invisible to the camera but still give reflections to objects on top of it.
This is very useful for making the ground render as alpha so I can composite objects into after effects.
I hope this feature is available now or soon, or it is a deal breaker for me to switch to this engine.
I'm looking forward to starting to use this centileo.

Also, I need to be able to catch shadows on the same ground plane and render out a shadow pass. Is this possible?
It seems all you want is possible right now. Just make a ground plane, drop a material with "Matte / Shadow Catcher" option On. Swich on Alpha Channel AOV - and it will render shadows on the plane, but will not show the plane in alpha channel. Also you can use Sphere (Omni) light sources or HDRI Sky with Shadow Cacher intensity to change the strength of shadows casted on matte/shadow cacher object
I tried and the render just shows my objects with no shadows on the plane and nothing else. It looks just like my regular beauty pass. I enabled alpha channel like you said, but it does not give me any shadows on my plane when I render a shadow multi-pass.

How do I make shadow pass work?
Also, whenever I render a multi-pass it still renders my beauty pass. How do I make it only render the multi-pass I want and not the original beauty pass? Doesn't this would waste a lot of rendering resources and increase rendering time?
Edited: ssjenforcer - Nov 14, 2021 18:11
 
Administrator  Posts: 593
Nov 17, 2021 19:42
You probably missed the "Shadow Catcher" flag in CentiLeo material for ground object. Check here pls https://centileo.com/forum/messages/forum19/message1556/396-shadow-catch-pass-_multi_pass_-does-not-...
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