Answers.Body: <p>Pretty sure this is due to the little sun icon - the "collapse transformations" icon.. 
  See more here: <a href="http://helpx.adobe.com/after-effects/using/3d-layers.html" rel="nofollow">http://helpx.adobe.com/after-effects/using/3d-layers.html</a></p>
  
  <p>It's to do with what order 3D comp layers are processed when they're precomped.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-10-14T13:10:42.227Z
Answers.Text: Yes, that worked thank you. I wrapped the pre-comp inside another pre-comp and collapsed transformations on the top two layers of pre-comp. People (waving animation) > People Wrap (Nothing going on here) > Icon People (Collapse transformations) > Main Comp (Collapse transformations).
Answers.UserDisplayName: Andy Cheeseman
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-10-13T20:56:28.300Z
Answers.LastActivityDate: 2014-10-13T20:56:28.300Z
Answers.UserDisplayName: tomh
Body: <p>I have two white shapes that overlap on a purple background, which are in a pre-comp. One in animated (an arm) and the other is not (the rest of the body).</p>
  
  <p>When I fade the pre-comp in, from 0 to 100 opacity, I can see the parts where the shape overlaps. This is made worse by having a motion blur, which seems to multiply the blur in that area.</p>
  
  <p><img src="https://i.sstatic.net/Ce4sR.png" alt="enter image description here"></p>
  
  <p>Do you know how to avoid this situation, and to have the two shapes behave as one.</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2014-10-13T14:04:33.613Z
Comments.Text: Are you fading in the parts of the pre-comp or are you actually using the pre-comp in another composition and fading in the entire pre-comp? This appears to be the result of a blending issue since if you aren't using a separate comp, you end up with two objects being blended at 50% but behind one object at 50% is another object at 50% which blocks out more than 50% of the background, thus you see the difference.
Comments.UserDisplayName: AJ Henderson
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2014-10-13T14:21:21.920Z
Comments.Text: The body and arm are two shapes in a pre-comp. Then the pre-comp itself has the opacity change animation on it.
Comments.UserDisplayName: Andy Cheeseman
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2014-10-13T14:35:55.770Z
Comments.Text: Hmm, no idea then.  The issue is definitely blending related, but I'm not sure the best way to fix.  It is treating it as 2 50% solids instead of 1 combined solid that is at 50%.
Comments.UserDisplayName: AJ Henderson
Tags: <after-effects>
Title: Shapes overlapped in pre-comp, transparent fade in visibility
UserDisplayName: Andy Cheeseman
ThreadText: # Shapes overlapped in pre-comp, transparent fade in visibility
  
  (Asked by: username_0 on 2014-10-13)
  
  I have two white shapes that overlap on a purple background, which are in a pre-comp. One in animated (an arm) and the other is not (the rest of the body).
  
  When I fade the pre-comp in, from 0 to 100 opacity, I can see the parts where the shape overlaps. This is made worse by having a motion blur, which seems to multiply the blur in that area.
  
  ![enter image description here](https://i.sstatic.net/Ce4sR.png)
  
  Do you know how to avoid this situation, and to have the two shapes behave as one.
  
  **Tags:** after-effects
  
  > **Comments:**
  > **username_1**: Are you fading in the parts of the pre-comp or are you actually using the pre-comp in another composition and fading in the entire pre-comp? This appears to be the result of a blending issue since if you aren't using a separate comp, you end up with two objects being blended at 50% but behind one object at 50% is another object at 50% which blocks out more than 50% of the background, thus you see the difference.  
  > **username_0**: The body and arm are two shapes in a pre-comp. Then the pre-comp itself has the opacity change animation on it.  
  > **username_1**: Hmm, no idea then.  The issue is definitely blending related, but I'm not sure the best way to fix.  It is treating it as 2 50% solids instead of 1 combined solid that is at 50%.  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_2 on 2014-10-13. Score: 0 | Accepted answer
  
  Pretty sure this is due to the little sun icon - the "collapse transformations" icon..
  See more here: <http://helpx.adobe.com/after-effects/using/3d-layers.html>
  
  It's to do with what order 3D comp layers are processed when they're precomped.
  
  > **Comments:**
  > **username_0**: Yes, that worked thank you. I wrapped the pre-comp inside another pre-comp and collapsed transformations on the top two layers of pre-comp. People (waving animation) > People Wrap (Nothing going on here) > Icon People (Collapse transformations) > Main Comp (Collapse transformations).  
  
  ---
  
  