Background behind glass

[erick3d]

hi
i need a little help to know workflow  to  change background behind glass in PS
here's a test i did on old project with VRAY, hope it's more explicit



i saw this
https://coronarenderer.freshdesk.com/support/solutions/articles/5000516227-how-to-render-alpha-channel-
https://corona-renderer.com/features/workflow-tweaks/

bt not sure it helps....

thanks

Erick

[Nekrobul]

You place background virst and then on top of it image it self saved in PNG.

[erick3d]

humm thanks
to be more clear....

my render is done saved in TIF with a sky behind glass, but client wanna change the sky

here my render


dos it means i have to make another render wihtout the plane  (sky) ?
sorry that's sounds not really clear for me

Erick

[maru]

Hi, sorry but I don't understand the problem. You should be able to render the image + alpha channel. Then use some compositing software to replace the sky. So if the image from last post is final and you do not want to re-render it, simply add CShading_Alpha render element and go to Scene > Render only elements.

[erick3d]

Thanks maru
but sorry i don't understand u too....
this is  my alpha.
as u can see , the glass panel are full white..


think i will need to remove the plane with the sky bitmap  and save it as png


I miss something for sure

[maru]

It must be a wrong material setup. Can you show your glass material's "advanced options" rollout in material editor?

[erick3d]

sure
her eit is
never paid attention to advanced otpion ,as it's not usual for me to have transparent glass.


so what should i do ?

Visible in masks = off
Alpha mode = "Default"

or

Alpha mode = "Always transparent"?

[maru]

Which Corona version are you using? This is how glass works for me in alpha channel. Can you show screenshot of the material from mateditor?

[erick3d]

latest version of corona

her's screnshot

[maru]

And can you show the rest of material setup? :)

[erick3d]

first tanks again for ur help and...patience ! lol

making some investigations by myself.....
It works  but the plane which contain the sky for background make a full solid alpha...just need to make "alpha contribution =-1" or remove it at all... (but render was made with it ..fucked client, fucked me , bad workflow)

here the screen

[maru]

first tanks again for ur help and...patience ! lol

making some investigations by myself.....
It works  but the plane which contain the sky for background make a full solid alpha...just need to make "alpha contribution =-1" or remove it at all... (but render was made with it ..fucked client, fucked me , bad workflow)

Oh. Actually this is a very important thing which I should have asked. How is the background made. I thought it's just an enviro override. Sorry. Let's hope we will be both smarter next time. :)

[erick3d]

hhaaa..but thanks anyway..have a nice day !