• Adobe After Effects

  Matte Showing on RPF Sequence

  Posted by 101creative on April 30, 2007 at 8:28 am

  I’m having a problem with a sequence that is being exported from 3ds Max. The edge is showing a matte.

  I am exporting from Max as a 16bit RPF sequence with straight alpha (NOT premultiplied). I’m getting a matte around the image.

  I have found that applying a “Alpha Levels” effect in AE7 does clean up the edge very nicely. However, I would like to find the best method for importing with the cleanest edges.

  I created a graphic that shows the problem I am having.

  https://www.timhull.com/out/Hendrick-16bit-Straight-Alp.jpg

  I would greatly appreciate any help with this!

  Thanks!

  Tim

  Tim Hull

  Kevin Camp replied 19 years, 4 months ago 3 Members · 2 Replies
• 2 Replies

• 

  Darby Edelen

  April 30, 2007 at 5:45 pm

  I think you might actually want to use a premultiplied alpha in this case, as long as you properly interpret the alpha when you import the sequence.

  It looks to me like the RGB channels you’re getting from Max don’t quite fit for a straight alpha. You want to get rid of that white outline around your text in the RGB channels. There may be a render setting in Max (I’m not too familiar with it) that you should change. Usually straight RGB images look very strange when you view them without their alpha, the RGB channels should spill over beyond the bounds of the alpha, but you have an odd white outline.
• 

  Kevin Camp

  April 30, 2007 at 8:03 pm

  i’ve seen this with an older version of cinema 4d (it may still be a problem with c4d, i don’t know). but since ae handles premultiplied images well if you tell it that the image/footage is premultiplied, i’ve stopped using the straight with alpha option in c4d if its going into ae.

  Kevin Camp
  Designer – KCPQ, KMYQ & KRCW

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