Lenzfx
>>…what we'd have is a reflection that is in perfect focus (since >>AD is our
focal range) superimposed upon a surface which is out >>of focus (since AB is
not our focal range). I'm trying to imagine >>how this would look but I'm
absolutely certain that it's nothing >>I've EVER seen in real life.
Hello Aaron,
I was going to keep out of this, largely because precise science is often
irrelevant in this field since most of what we do is subterfuge and trickery.
But although it may not detract one bit from the usefulness of your your
software to 3DSers everywhere, there is some confusion here. I work at a
national lab with a group of scientists and optical experts, and I can point
you towards reference material if desired. We run several laser and optics
labs with specialties in fiber optic systems, image processing, and
thermographic imaging.
The case of a partially reflective surface is more complex, however with a
near 100% reflective surface such a mirror at B in your diagram, you do IN FACT
focus on C as if it were actually at D. If you want a simple example, try this
experiment: with an ordinary (focusable) 35mm camera, stand about 2 ft from a
bathroom mirror. Place a piece of tape on the mirror surface for reference and
focus on your reflection in the mirror. Note that when your reflection is in
focus, the tape (and the mirror surface and the mirror frame) are very much out
of focus. In a nutshell, you can treat a plane mirror as a thin lens with a
magnification of unity (check any college physics book.)
Now a partially reflective surface is a different story, depending on to what
extent the reflections are diffuse or specular (you can simulate this to some
extent by placing layers of plastic wrap on the mirror), and when the surface
is not flat, it gets much more interesting.
It is not surprising that there is some confusion here, since the concepts
around virtual imaging are often conceptually challenging. <g> Even simple
lens concepts are difficult, especially when considered relative to the virtual
imaging in the eye. (When faced with virtual imaging calculations involving
compound lenses, I always run posthast down the hall and talk to Dave Sitter,
PhD!)
All this said, I agree with Gary Yost's carefully worded statements,
"There are always some inherent physical differences between
doing things via scanline rendering instead of with raytracing, but
since raytracing takes about an order of MAGNITUDE more time to
compute, any production animator would take the scanline method ANY
DAY OF THE WEEK…"
and
"…your optics package is going to be one of the most valuable
tools a 3D Studio animator could have…"
I agree that the tremendous potential of your program, regardless of the
precise technical tradeoffs involved, will make it one of the most used IPAS
routines yet. The bottom line is not "how did you get there" but "how does the
result look."
JKJ