Subject: Re: Shifting Motions
From: Perry Harovas <[email-masked]>
To: [email-masked]
Cc: [email-masked]
Date: Wed, 27 Jul 1994 14:40:55 -0400 (EDT)

On Mon, 25 Jul 1994 [email-masked] wrote:

> Perry Horavas writes:
> 
> >
> >On Sun, 17 Jul 1994, HURTT CHRISTOPHER MICHAEL wrote:
> >
> >>       Another great feature would be "Shadow Casting Only" toggle
> >> for objects. An object would cast a shadow, but not be renered or show
> >> up in the Alpha channel. Good for when using multile layers and compositing.
> >
> >Again, I TOTALLY agree. I have had to do this _many_ times, and again,
> >hack to the rescue!
> 
> 
> 	????  Really?  Why?  Please expand on why this is such a neat thing
> and is so useful, cuz I can't really think of a regular application for it.
> 
> 	Thanks!
> 
Well, I'm reading and replying to this at siggraph, and the `internet 
police seem to be hovering near me (maybe I'm on too long), so I will 
make this brief. I have needed to use this (hopefully future) feature to 
do special effects where I wanted to cast a shadow, but not have the 
object visible. This was to create a "shadow" character that moved 
through the scene. The only way around this, was doing it in two layers, 
and compositing (using and object and a front projection image map to 
recieve the shadows). The reason that this is not the best way around 
this is (in addition to the extra time needed to set up an render the 
composite scene), the lighting of the object that will cast shadows has 
to be fudged to allow the object to be off camera (so that it is not 
_visible_). This caused some shadow reality interaction problems that 
made it hard to make this scene realistic. If this "shadow only" thing 
were an option, I would have been much more productive (and happier).

Sorry, but I need to move on now (so MUCH to see!!!!!!!!!) :-)

See everyone Friday when I'm back!

-Perry Harovas