camera near/far fade

Posted by Greg Brannen on August 28, 2008 at 8:43 pm

startFade = 500; // Start fade 500 pixels from camera. 
  endFade = 1000;  // End fade 1500 pixels from camera. 
  try{ // Check whether there's a camera. 
      C = thisComp.activeCamera.toWorld([0,0,0]); 
  }catch(err){ // No camera, so assume 50mm. 
      w = thisComp.width * thisComp.pixelAspect; 
      z = (w/2)/Math.tan(degreesToRadians(19.799)); 
      C = [0,0,-z]; 
  } 
  P = toWorld(anchorPoint); 
  d = length(C,P); 
  linear(d,startFade,endFade,100,0)

HI.

I am trying to fade objects based on their distance to the camera.
I found an expressions that fades as the object moves away from the camera but I need it to also fade as it gets near the camera.

Thanks for any help.

Michiel Wesselius replied 14 years, 2 months ago 4 Members · 8 Replies

8 Replies

Dan Ebberts
August 28, 2008 at 11:55 pm

This should do it:

startFadeNear = 300;
endFadeNear = 500;
startFadeFar = 800;
endFadeFar = 1500;
try{ // Check whether there’s a camera.
C = thisComp.activeCamera.toWorld([0,0,0]);
}catch(err){ // No camera, so assume 50mm.
w = thisComp.width * thisComp.pixelAspect;
z = (w/2)/Math.tan(degreesToRadians(19.799));
C = [thisComp.width/2,thisComp.height/2,-z];
}
P = toWorld(anchorPoint);
d = length(C,P);
if (d < endFadeNear){ linear(d,startFadeNear,endFadeNear,0,100) }else{ linear(d,startFadeFar,endFadeFar,100,0) } Dan
Greg Brannen
August 29, 2008 at 12:51 am

Wow! Great to have a community like this.
Nice to have someone who knows what they are doing out there.

Thanks for your help.

I really appreciate it.

Thanks again Dan,

Greg
Danny Jenkins
May 10, 2010 at 8:24 am

Hi Dan, first of all thanks for all the time you put into helping us out on here!

Now this one from above isn’t working for me in AE CS4:

startFadeNear = 300;
endFadeNear = 500;
startFadeFar = 800;
endFadeFar = 1500;
try{ // Check whether there’s a camera.
C = thisComp.activeCamera.toWorld([0,0,0]);
}catch(err){ // No camera, so assume 50mm.
w = thisComp.width * thisComp.pixelAspect;
z = (w/2)/Math.tan(degreesToRadians(19.799));
C = [thisComp.width/2,thisComp.height/2,-z];
}
P = toWorld(anchorPoint);
d = length(C,P);
if (d
linear(d,startFadeNear,endFadeNear,0,100)
}else{
linear(d,startFadeFar,endFadeFar,100,0)
}

After Effects warning: Expected: )
Expression disabled.
Error occurred at line 15.

Just need this expression to fade in AND out in relation to distance from camera! Thanks again for any help!

Danny
Dan Ebberts
May 10, 2010 at 1:58 pm

It looks like the 14th line got chopped off when I posted the expression. Change it from this:

if (d

to this:

if (d < startFadeFar){ Dan
Danny Jenkins
May 10, 2010 at 11:17 pm

Thanks Dan! Didn’t know how much luck I’d have digging this up from’08 haha.

I found your expression site as well, hope to see you still working on it, it looks great!

Danny
Michiel Wesselius
March 19, 2012 at 3:02 pm

the correction doesn’t appear to work in 5.5.
Is this possible or am i missing somthing?
Dan Ebberts
March 19, 2012 at 3:48 pm

I can’t think of a reason it wouldn’t work in 5.5. Are you getting an error message? If not, is the expression doing anything?

Dan
Michiel Wesselius
March 19, 2012 at 4:06 pm

Sorry, it appears my browser didn’t preview the correction properly, now it works correctly. Thanks1

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camera near/far fade