Subject: checking for next release

From: Dave Stampe-Psy+Eng <dstamp@watserv1>
Date: Tue, 11 Aug 92 22:51:09 -0400

Some things have come up for the next release that might be important,
and I'll need feedback to see how disruptive they'd be to those who
have written code already.

First, the rotation of the segments may be the inverse of what is 
expected.  I'm checking it out, but I need to know: how many
people have written software that would be adversely affected by
a change in segment rotation effects?  Basically, the rotations
alone would be the same, but in combination they'd act differently.
Right now, the rotation order is YXZ in world->camera format, but
this might be wrong for segment rotations.

On the same topic, the angle directions are probably not correct
for the left-handed coordinate system.  Comments?  Problems if 
one or more of pan, tilt, and roll are negated in the next release?

A final structural note.  REND386 places objects directly in the world,
keeping object coordinates for use in segment repositioning.  As you
know, most other systems only keep object coordinates, then combine
the object position and view matrix to render the object.
Now, to do this in REND386 would slow the system by about 20%, and
would not decrease memory requirements to speak of.  It might allow
the reuse of object representations, but probably not their recoloring.

Can anyone think of an overriding reason to go to this method?  It would
be transparent to older software, of course.  But it would be a lot of
work, and slow the system, so I need some damn good reasons first.

- Dave Stampe

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From: [email-masked] (Christopher Phillips)
Date: Wed, 12 Aug 92 16:58:12 WST

> the reuse of object representations, but probably not their recoloring.
 20% seems like a very high figure. Would an extra 9 multiplyaccumulates
per vertex per frame really take that much time?  How are viewpoints 
currently managed?

Christopher Jam	__________________________________________________
'Another day, another try.  But remember, SHOOT OR DIE!' -turrican
[email-masked]		c64 forever!!!!
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