Announcement

Collapse
No announcement yet.

coloured alpha

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • coloured alpha

    I have refractive object with color fog. Affect channels is set to "affect all chanels". I get coloured alpha.
    How can I use this kind of alpha? In Natron for example?

  • #2
    You have to use V-Ray's own file output, and keep "save alpha" checkbox enabled. No software out there supports colored alpha channel, because EXR standard doesn't. Therefore alpha with color has to be saved as a separate file/sequence where alpha is written into RGB channel. It's most useful when compositing matte/shadowcatcher objects that have been lit by colored lights (which is almost always the case).

    Comment


    • #3
      Thx for answer.
      Ok - so when I render alpha to separate file how can I use this file in Natron? This is maybe dumb question but I have animation with coloured glass and i have to output this as png files with transparency.
      When I import exr files to natron I lose color on the glass...
      I do animation and compositing in Natron rather rarely
      ___
      sorry for my English

      Comment


      • #4
        You invert the colored alpha, then multiply it on background, and then add beauty pass on top of that (after removing the monochromatic alpha from it).

        Comment


        • #5
          Thx this works

          Click image for larger version

Name:	glass.JPG
Views:	1
Size:	42.9 KB
ID:	867710

          But - is there any way to render this to transparent png without background?

          Comment


          • #6
            No idea... I would never use PNG when rendering anything I plan to compose in post

            Comment

            Working...
            X