Re: Best Anaglyph colors

[P3D Larry Berlin <lberlin@xxxxxxxxx>]

>Date: Mon, 19 May 1997
>From: P3D  Adam L. Beckerman  writes:
>............ I just bought Truespace by Caligari (a "3D" modelling
package), and what 
>I am wondering is:
>
>1.  If I create a "3D" object in Truespace and save two  images of it from two 
>perspectives (L and R, presumably as close to 2" apart as I can get -- per
a tutorial I 
>read on someone's website), then I perform the necessary operations in
Photoshop for 
>overlaying the images with the R/G values properly handled, can I expect to
get a 
>decent-looking anaglyph (true 3D)?  If not, why not?

*****  Simple answer, Yes. There is no reason with TrueSpace to have to
guess about the outcome of your images and no reason to have to worry about
a 2 inch separation of the cameras. Set up two cameras side by side with
each one assigned to a separate preview window, and glue the cameras
together. You can arrange the two preview windows side by side and freeview
your wire frame or rendered images to make sure you have what you want as
far as framing, distance from the object, stereo baseline and the related
visible depth, etc. BEFORE rendering to a file. Don't waste time rendering
what doesn't work.  If you aim the combined camera-object at the center of
the subject (you may need to adjust where that center is) then you can
freeview the wire frame in real time while dragging the cameras anywhere you
like. It's easiest to do this while dragging and watching your camera
locations in a preview window which is off to the side of your other windows
and is set up to view from above. This lets you make sure you get just the
right vantage point. You can change the distance between the cameras too, as
needed. Write me personally if you need more specific information.

This technique takes the gueswork out of wire frames too! In 2D they all
look alike and very little clues as to which line is in front of the others.
In stereo, such things are very obvious. Freeviewing is Freedom in 3D!!!
It's the single most valuable stereo related skill in natural existence!

>
>2.  If I create the object in color and do the same thing w/o converting to
greyscale, 
>what colors should I use for maintaining the best quality color anaglyphs?

******  Stay away from using colors in your image that are the same as or
close to your depth code colors. I use red/blue, if I make anaglyphs. I've
seen color anaglyphs that sort of work but I still prefer grayscale
anaglyphs. Download the program called *3D Photo Factory* for the easiest
way to make color or grayscale anaglyphs. It can be found at:

http://members.gnn.com/tronix3d/html/index.htm

>
>3.  If I produce two .avi (movie) files of the object 'flying' at two
'cameras', 2" apart (this 
>is just an example -- I'm not one to further the misconceptions about 3D),
is there a 
>good software package that anyone has used (maybe Adobe Premiere?) that
will allow 
>me to overlay the movie files and perform similar manipulations as the
plain images?  
>What sort of quality can I expect from this?

*****  Make sure that each of the AVI's is composed of the same number of
frames. Most basic AVI players let you advance frame by frame. I copy a
frame to the clipboard and then paste it into a program that will let me
assign each image to a different color channel, creating an anaglyph image
frame. Finally reassemble the AVI from your combined anaglyph frames.
Several programs let you edit and work on AVI's in this way. An old DOS
standby available through several books on PC Movie making is called *Dave's
Targa Animator*.  If you are using 3D Photo Factory to make the anaglyphs,
it doesn't have clipboard support yet, so you will have to make an interim
file for each image in order to input it into 3DF.

>
>4.  How closely do the color values I use to separate the image views have
to match 
>the glasses I have?  Presumably, the closer the match the better the 3D
effect, but has 
>anyone had any experience with better effects from poorly matched glasses
filters/color 
>separations?

*****  I've had very little experience with different glasses but the
inexpensive red/blue ones I own work fine with the red/blue channels on my
monitor. This might vary according to either your glasses, or the particular
model and make of your monitor. Experiment with it. The closer the match the
better exclusion there will be. It's fun to view a color picker graph in any
graphics program with red/blue glasses. You can see pretty clearly where in
the total spectrum the exclusion for your glasses works best, it appears
blackest at those points. It will also help you choose which other colors to
use, by how mutually acceptable they will be through both filters.

Larry Berlin

Email: lberlin@xxxxxxxxx
http://www.sonic.net/~lberlin/
http://3dzine.simplenet.com/


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