• Adobe After Effects

  how to make a back light shape an object?

  Posted by Camilo Pinilla on November 21, 2007 at 5:41 pm

  Hi, i’m trying to make a spot light to border an object, like when a person is between the light source and the viewer and we only see the silhouette. I’ve tried to make the spot light with trapcode lux, but i cannot get the spot effect putting the light behind.
  i would like the light to border the silhouette like when i use cc radial fast blur to blur something.

  thanks for your help,

  Camilo Pinilla replied 18 years, 6 months ago 3 Members · 6 Replies
• 6 Replies

• 

  Darby Edelen

  November 22, 2007 at 8:14 am

  [Camilo Pinilla] “i would like the light to border the silhouette like when i use cc radial fast blur to blur something.”

  You just posted a potential answer to your post… in your post! =D

  Try applying a Radial Blur to a duplicate of the layer to be backlit. Set the Center to the location of the light, you can apply this expression to the center property:

  l = thisComp.layer(“TheLight”);
  l.toComp([0,0,0]);

  Now use this Radial Blurred layer as an Alpha Inverted Track Matte for your Lux layer and you should be golden. It’s not a perfect solution, but it’s a good start. You should also consider creating some light wrap using a similar technique and a Box Blur.

  Darby Edelen
  Designer
  Left Coast Digital
  Santa Cruz, CA
• 

  Camilo Pinilla

  November 22, 2007 at 1:35 pm

  I think i have a problem with the order of the elements, because i don’t get it, so this is what i have in the time-line:

  1. Camera

  2. Adjustment Layer : Trapcode Lux (reach comp layer off)

  3. TheLight :

  position:

  l = thisComp.layer(“TheLight”);
  l.toComp([0,0,0]);

  4. Logo image

  5. Duplicate “Logo image” : radial blur (zoom) Alpha Inverted
  Track Matte

  I see the light like if it were a point light, so no ray. and my logos image are invisible???
• 

  Camilo Pinilla

  November 22, 2007 at 2:04 pm

  The effect i want to make it’s something like the beginning of this film
  https://xplsv.tv/moviePlayer.php?id=1722
• 

  Sam Moulton

  November 22, 2007 at 3:26 pm

  CC Light Burst or Trapcode Shine
• 

  Darby Edelen

  November 22, 2007 at 5:10 pm

  [Camilo Pinilla] “2. Adjustment Layer : Trapcode Lux (reach comp layer off)”

  I don’t know if this matters in this case, but I don’t like to put Lux on an Adjustment Layer, I put it on a solid.

  [Camilo Pinilla] “3. TheLight :

  position:

  l = thisComp.layer(“TheLight”);
  l.toComp([0,0,0]);”

  The expression should not be applied to the light, it should be applied to the Center property of the Radial Blur effect on the duplicate of your footage.

  [Camilo Pinilla] “5. Duplicate “Logo image” : radial blur (zoom) Alpha Inverted
  Track Matte”

  Apply the expression to the Radial Blur on that layer.

  Darby Edelen
  Designer
  Left Coast Digital
  Santa Cruz, CA
• 

  Camilo Pinilla

  November 22, 2007 at 5:40 pm

  Thanks!!!!
  it works! well, as a back light everything is good, that’s what i need for the moment, but it would be another task to see oneday if we want to turn the camera and see the other side, because it doesn’t look the same effect. But for the moment it’s ok for me, thanks a lot for your help.
  I’d like to ask a simple question, because i’m new in after effects, why is it better to put the lux effect in a solid layer ? why isn’t a good idea to put it in an adjustment layer?

  Thanks

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