barn doors effect on AE CS4 lights

[Michael Szalapski]

Make a 3d layer and use it as a barn door. Make sure it’s set to cast shadows and the layer it’s casting the shadow onto is set to accept shadows.

– The Great Szalam
(The ‘Great’ stands for ‘Not So Great, in fact, Extremely Humble’)

No trees were harmed in the creation of this message, but several thousand electrons were mildly inconvenienced.

[Tudor “ted” jelescu]

Interesting question. I do not know if there’s a way to adjust the shape of the light- maybe there will be someone who can help with that- but what you can do, is to have a 3d layer (black square, 400×400 pixel or so) with a mask (rectangle) cut in the middle, set in front of your light (perpendicular on the beam) and parented to it. Turn cast shadows on and there you have it- by manipulating the sides of the mask you get pretty much the same effect as you would from barn doors.

Tudor “Ted” Jelescu
Senior Compositor/VFX Artist
Bucharest, Romania

[Zack Gietek]

That’ll do it!! thanks guys–that’s great. I just have to make sure I set the light w/ ‘barndoors’ mask BEHIND the cam, as to not see it in my frame- SWEET!

thanks again

[Jon Bagge]

That’ll do it!! thanks guys–that’s great. I just have to make sure I set the light w/ ‘barndoors’ mask BEHIND the cam, as to not see it in my frame- SWEET!

If I remember correctly you can set the barndoor layers to ‘shadow only’. That will make them invisible to the camera but they will still cast shadows. Thus you can have them in front of the camera without causing a problem.

————–
Jon Bagge
Editor – London, UK
Avid – FCP – After Effects

[Steve Roberts]

Yes, but it should be noted that to completely cut off the light where the mask is, the light’s shadow darkness have to be set to 100%. This would mean that all shadows cast by the light would be 100% dark.

I can’t think of an alternative right now. Hm. Anybody?

[Zack Gietek]

I just used an ambient light at about 15-30%, to combat that

[Steve Roberts]

Hmm … but wouldn’t the ambient light affect all shadows — those cast by the mask and those cast by other elements such as text? In other words, wouldn’t it dilute the darkness of the barn door effect?

[Zack Gietek]

sure it would, but I guess it depends on the application, in my particular situation, I’m only using the lights against, 2d plains- I’m highlighting text on documents- no 2.5d or 3d elements here….so I’m highlighting text, yet still want to see the rest of the document ‘in the shadows’ so to speak–without the ambient light, it is black everywhere except for what I am highlighting. So it’s a little give an take with the light intensity levels between both lights to achieve the desired effect…..and for me it’s working 😉

[Steve Roberts]

Well, there ya go. 🙂