Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] Feature Requests => [Max] Resolved Feature Requests => Topic started by: Naxos on 2017-03-27, 19:21:37

Title: non-relevant alpha needed...
Post by: Naxos on 2017-03-27, 19:21:37
Hello there,

Corona has alpha forced to black, or forced to white, but how can we set alpha ignored for an object ?

I mean, sometimes we need an object to be alpha-seen regardless of the alpha of another object.
For that Vray has alpha going from -1 to 1 :
-1 : forced black
0 : ignored
1 forced to white

Regards
Title: Re: non-relevant alpha needed...
Post by: Ondra on 2017-04-01, 23:14:47
does making the object invisible to masks (in coronamtl advanced properties) help?
Title: Re: non-relevant alpha needed...
Post by: Naxos on 2017-04-03, 09:13:16
Exactly, many thanks...

Last need with alpha is to get alpha in reflexions / refractions (request alreay posted somewhere)...

Regards
Title: Re: non-relevant alpha needed...
Post by: hodryc on 2017-04-03, 11:18:17
The only problem I see with "visible in masks" option is that if there is an object behind it visible to alpha, the option doesn't override it. What I mean is that would be great if we could have a way to remove it from alpha channel even if there is another objecto on the background covering it.
Title: Re: non-relevant alpha needed...
Post by: Naxos on 2017-04-03, 13:41:21
The only problem I see with "visible in masks" option is that if there is an object behind it visible to alpha, the option doesn't override it. What I mean is that would be great if we could have a way to remove it from alpha channel even if there is another objecto on the background covering it.

I guess this is the "always black" option, isn't it ?
Title: Re: non-relevant alpha needed...
Post by: tony_morev on 2017-04-24, 20:02:27
"always black" = -1

i gotta say after using Corona for a while i still think V-ray had this set up better
object properties were a lot easier to set up for proper alpha than materials
Title: Re: non-relevant alpha needed...
Post by: Naxos on 2017-04-25, 09:23:10
"always black" = -1

i gotta say after using Corona for a while i still think V-ray had this set up better
object properties were a lot easier to set up for proper alpha than materials

Setting this within a material can help in some cases : you can have 2 materials with different settings put into a multi-sub material, and animate a material modifyer... i use that all the time...
Title: Re: non-relevant alpha needed...
Post by: tony_morev on 2017-04-25, 18:49:27
i suppose
everyone has their own workflow
for us it's mostly masking objects, and being able to do that with object selection takes a lot less effort
Title: Re: non-relevant alpha needed...
Post by: Naxos on 2017-04-26, 09:47:48
In my last large project (billards configurator), i had to render out more than 150 000 png files... so all was set as a large animation for a specific model...
Animating the ObjectID is not easy, animating a material ID modifyer is simple... this is the reason why.
Title: Re: non-relevant alpha needed...
Post by: Naxos on 2017-04-26, 09:49:21
The topic stills needed : alpha to be ignored, so not "always black", nor "always white"...
something like "alpha ignored"...
Title: Re: non-relevant alpha needed...
Post by: Ondra on 2017-06-09, 19:50:39
duplicate for the last request: https://forum.corona-renderer.com/index.php/topic,15599.0.html