Knoll Light Factory - Location Layer ?
by Paul-Emile Boucher
on
Aug 25, 2008 at 3:57:04 pm
Hi,
First of all, i'm sorry for my poor english, i'll try to be as understandable as I can. Don't hesitate to ask if i'm not.
I'm using Knoll Light Factory plugin for AE to create a realistic sun in an animated footage. My composition is made of about 10 layers placed on the Z axis, with a camera in front of them. It's a kind of Camera Mapping effect, with several 2D grounds : nothing very unusual. The first ground of the scene (grass) has a position of -1000 on the Z axis, and the last one (sky) has a position of 1000. The camera is doing a soft elevating movement.
My purpose is to create a flare effect coming from the sky groud. With Knoll light factory, the source location can't be set on the Z axis (only X,Y). I tried to use the "Location Layer" setting, and to set a 3D layer as location for my sun. Light Factory is supposed to search the alpha channel of the location layer for any non-black pixels, to calculate the average position of those pixel, and to place the light effect at this location.
Therefore, I created an alpha layer in photoshop, completely black, with a small white dot on it, and made it a 3D layer (Z position = 1000) in my AE comp. But when this layer is set as a Location Layer for my flare, light factory doesn't seem to recognize the white dot : the light just disappear.
Do you know how to fix it ? Is there an other way to make this effect ? With an expression, maybe ? I just want the flare to act as if it was generated by a still dot from the 3D space (so that his direction depends on the camera positon)...
Re: Knoll Light Factory - Location Layer ? by Darby Edelen on Aug 25, 2008 at 4:53:32 pm
I don't have Light Factory on my computer at my new job, so I can't check to see if I'm remembering correctly, but it takes a 2D position for the flare, correct?
I think what you'd want to do is create a 3D Null, place it where you want the source of the flare in the scene, then use an expression on the Light Factory effect's position to convert the 3D position of the Null into a 2D position on the layer:
l = thisComp.layer("FlareNull");
l.toComp(l.anchorPoint);
Your Light Factory effect will need to be on a comp-sized solid or adjustment layer for this to work.
