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View Full Version : ARGH! I must be missing something with render exporting. Help!



TheDynamo
07-07-2008, 01:06 PM
I have something I'm trying to turn into a particle in After Effects. When I export a 32 bit image, the nice specular highlights that you see in version A do not come out in version B (which is the one with the premultiplied alpha). Is there an output filter that I am missing to include the specular highlights? Thanks in advance!

trentonia
07-07-2008, 02:16 PM
It's hard to tell against a white background, but try rendering with "render transparency" turned off.

TheDynamo
07-07-2008, 02:34 PM
I am rendering these out to being 32 bit PNG files using the classic camera. I have tried turning on and off the various raytrace options in the renderer panel as well as playing with the individual surface settings with no specular/reflective data appearing in my alpha channel information.

Attached is a picture describing this.

-Dyn

CC Rider
07-07-2008, 02:42 PM
Try rendering the alpha channel out as a seperate file then use it in after effects as a luma mask.
Also sometimes the "remove matte" effect in AE can help make transparency effects Pop a little better.

TheDynamo
07-07-2008, 03:35 PM
No dice, the only way that works is if I blend the alpha with the foreground. Then would have to take the same two layers and duplicate them making the specular highlights an additive key underneath the alpha. It's a hell of a workaround for something that should come out when you render this with an alpha channel. Has anyone tried to render a glass-like object as an alpha channel cut out before? That's more or less what I'm trying to accomplish.

-Dyn

xchrisx
07-07-2008, 04:09 PM
just out of curiosity have you tried using renderbuffer export for reflection and spec then combining them in post?

TheDynamo
07-07-2008, 04:14 PM
I'll see if I can find that. Is that a shader found in the compositing/etc window?

-Dyn

CC Rider
07-07-2008, 05:12 PM
No dice, the only way that works is if I blend the alpha with the foreground. Then would have to take the same two layers and duplicate them making the specular highlights an additive key underneath the alpha. It's a hell of a workaround for something that should come out when you render this with an alpha channel. Has anyone tried to render a glass-like object as an alpha channel cut out before? That's more or less what I'm trying to accomplish.

-Dyn


You could render once normally and then do another render with the transparency back down to 0 for the cap to get your alpha.
Then you could combine the 2 in AE and use the technique I mentioned before.

I'm sure there is a way to do this properly but, in the abscence of the correct way, this will get you out of a pinch at least...
:D

Sarford
07-07-2008, 07:12 PM
Did you use 'flare to alpha' in the image processing window?

TheDynamo
07-08-2008, 03:12 PM
The flare to alpha thing worked. It's strange that you have to use a secondary process to get what should be part of a regular alpha channel. For example, if you can't see through a part of the object the alpha is white regardless of what is causing the opacity.

Thanks for the help guys, I was almost to the point of sleeping on my v9 manuals in the hopes to learn via osmosis.

-Dyn