Subject: Re: Fader video in 3.5 ?
From: Mark Thompson <[email-masked]>
To: [email-masked]
Date: Tue, 13 Sep 94 11:42:43 EDT

> In Lightwave 3.5 the option save fader alpha mode does not work properly
> went use with lens flares, the alpha render the lens flare fully white just
> like it's RGB conter part, wish creates a lens flare that is complily
> opaque?

I talk about this and other alpha issues in great length in a recent issue
of LWPro. This is one of the downfalls of fader alpha mode.

> Is there a trick to compose lens flares outside Lightwave with out losing
> there colors?

For lens flares, you should render them against a black background without
fader alpha (in fact don't even bother to save alpha at all). Then import
the flare images into your compositing software with an absolute add
operation (ie. simply add the pixel values to your image without any blending).
This can be done in ImageFX, but I'm not sure what other software has an
absolute add operation.
%~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~%
%      `       '        Mark Thompson                 CONCURRENT COMPUTER  %
% --==* RADIANT *==--   [email-masked]        Principal Graphics   %
%      ' Image `        ...!uunet!masscomp!mark       Hardware Architect   %
%     Productions       (508)392-2480 (603)424-1829   & General Nuisance   %
%                                                                          %
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~