corona shadow catcher material

[LorenzoS]

Hi everyone,
i have a little question:
on the alpha mode option there are 3 choise- "always solid" - "for compositing" "always trasparent", i need "always solit" and "for compositing", so i had to render double times.
(I need "for compositing" to obtain the alpha channel that i use for shadows in post production.)
Someone know if there is the possibility to render in one time?

Thank you

[maru]

Not sure if this is the solution you need, but a CMasking_Mask element will give you a solid mask for your shadowcatcher, in one go:

[LorenzoS]

Thank you maru for your answer,
with that metod you obtain also the beauty pass with the backplace visible?

[LorenzoS]

sorry, backplate, not backplace

[LorenzoS]

Not sure if this is the solution you need, but a CMasking_Mask element will give you a solid mask for your shadowcatcher, in one go:

Yes it's a good solution.
Only when i have glass in scene i suppose it don't work because CMasking_Mask don't support opacity.

[maru]

Thank you maru for your answer,
with that metod you obtain also the beauty pass with the backplace visible?

No, the beauty with backplate won't be there as we are using the "for compositing" mode of shadowcatcher.
But you can just drag and drop the backplate in PS or other software, right?

Only when i have glass in scene i suppose it don't work because CMasking_Mask don't support opacity.

Can you explain or post examples of this problem?

[LorenzoS]

No, the beauty with backplate won't be there as we are using the "for compositing" mode of shadowcatcher.
But you can just drag and drop the backplate in PS or other software, right?

Right, i undestand.

Can you explain or post examples of this problem?

My english is so poor, and mybe i dont undestand well the workflow in shadowcatcher, but in my opinion the best way should be to calculate the alpha mode for compositing in one go togheter the solid or trasparent mode.
But maybe that is not possible.