Subject: Re: Additive?
From: Mike McCool <[email-masked]>
Cc: [email-masked]
Date: Tue, 31 Oct 1995 21:38:10 -0800 (PST)

My first taste of additive was thanks to Dave Warner, who showed me that 
it was applicable as a sort of easy substitute for clipmapping.  

I had some frames of a gas explosion that I'd digitized from a movie, and 
I wanted to import them as a more realistic looking explosion in an 
anim.  The frames were mostly black background, with the fireball 
blooming in the center. 

Rather than have to produce a greyscale and then reverse it for every
color frame and then apply BOTH the color map and it's reversed greyscale
as a clip map to every frame, I just applied each color map once, in
sequence, and with the ADDITIVE button clicked. All the dark background 
colors of the map were clipped away, and I got a perfect explosion 
sequence. 

If you can make sense of the gobble-de-gook of that last paragraph, 
don't forget to turn all shadow options OFF when applying ADDITIVE in 
this way.  Otherwise the object won't appear transparent, and objects 
behind will look weird. 

And again, it's DAVE WARNER who deserves credit for this trick. 
--
Mike McCool <[email-masked]> sent this message.
To Post a Message           : [email-masked]
Un/Subscription Requests To : [email-masked]
(DIGEST)                 or : [email-masked]
Administrative Items To     : [email-masked]