Question about Arnold PNG export

N3db

I have a question, hopefully someone can help me, how I can export as PNG a final render using Arnold without seeing the ground and the shadow can be used under any surface, with white surface it seems integrated the png exported from maya but with dark surface the shadow seems grayish as a stain as I can do to have a transparent shadow that can be used on any background, that does not do this

I want it to look integrated into any surface and not look gray like in the first image

oglu

Use EXR for final export.
PNG isnt the right format.

N3db

Hello thanks for replying, I save it as .exr but that light keeps appearing all over the shore and the shadow is white, which I can do what kind of material I use for the infinite background or as I do to make the shadow look good

N3db

those lines and that white shadow as I can do to make it shadow used on any surface
                          

poopipe

You should be rendering passes separately if you want to composite stuff together after. 

Have a look through the instructions

N3db

hello

where i can find a good tutorial for this? im trying even with separates AOV something i'm doing wrong 

Eric Chadwick

Check the documentation. And look for a shadow pass, also an occlusion pass.

https://docs.arnoldrenderer.com/plugins/servlet/mobile?contentId=81727188#content/view/81727188

gnoop

I haven't used Arnold  for years   and  forgot everything about it already.     But to render just a beauty de-noised  pass with such a shadow  requires a  black background, not white, in the actual rendered picture   and  having the actual background  still  reflecting  in your object material .

     

  Usually all renderers have a way  to do so one way or another .    Sometimes it's called  render layers .   Sometimes  ray miss/switch  shader ,   shadow catch material, etc .    Sometimes it's  special AOV   you construct in a shader node editor that output only  objects  you need  on a black background  and the shadow in a separate shadow only AOV.

I don't remember Arnold exact way but usually it's even a few different approaches.

I recall Mental ray had just special shader for backgrounds to do so , perhaps Arnold have something quick and simple too.

Once you have your thing rendered against the black background  you can put  the alpha over with "divide" blending in Photoshop 32 bit mode or just have "un-premultiplied" output checked in   in your soft.   

ps.  for your already rendered picture  I would try  just to multiply alpha of the backed (without shadow) over .   You could  get it from cryptomatte AOV  and Photoshop free  exr-io  plugin.