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b) Methods for the 3D visualization technology based on 
stereo mates, projected in contact are 
• projections and black and white appearance, like for 
anaglyphs (complementary colors), with projections and 
false color appearance, as for 
• chromadepth, with a 3dimensinal appearance of a 2 
dimensional image, calculating shifting in (particular) 
spectral colors, as verified, using special prismatic 3D 
glasses, suited for spectral splitting; colors appear partly 
strange. 
• The polarizing filters method today is the method mainly 
in use for public 3D (slide) shows, even for huge images 
on Al-screens. This method allows projections with 
colored appearance, as verified by using 2 differently 
polarized images on the screen, to be observed using 
glasses, showing the same polarization as the projection 
devices. 
• TEKTRONIX is the pendant to the polarization method 
suited for PC as well as for video. The screens are covered 
by steered polarization filters to be viewed with common, 
but suited polarized glasses. 
• Currently a PC suited state of the art method for a 
projection of stereo mates and colored appearance are 
liquid crystal shutters, the successor of the antique shutter 
glasses. 
• Alternate projections of dynamic stereo mates in particular 
and colored appearance are applied for the Nuoptix method 
as invented by PULFRICH: To obtain a 3D impression in 
color, a particular video sequence is shown on an 
ordinary(!) TV screen, but viewed with sun glasses with 
one missing dark glass, causing a slightly delay in the 
perception time of each eye. Therefor video sequences are 
suited for direct stereoscopic visualization, if they have in 
principle been taken from a moving platform (e.g., car, 
train, boat, airplane) perpendicular to the moving direction. 
• In the opposite case of a fixed video camera platform, the 
object must show a perpendicular movements to the 
camera direction. 
• These kind of Nuoptix glasses are also required for a 
spatial perception of a queue of central perspective 
projections (2.5 D) 
c) Methods using virtually 3 D Models are 
• The FELIX-3D solid state cube is the static successor of 
the well known FELIX-3D cylindrical Plexiglas tube 
with rotating screen, both suited for the presentation of 3D 
Laser based models, to be generated in color and in real 
time (but so far not in real color) for a direct 
autostereoscopic visualization, which means, for unaided 
eyes, see Figure 1. The FELIX-3D allows an object 
projection within a 3D crystal glass cube. Spatial forward 
intersection of 2 infrared Laser beams, verified as Two- 
Step Upconversion, gains the Voxels. 
• holographic methods off different provenience, lacking 
true color. 
3. TOPICS FOR FUTURE RESEARCH IN SPATIAL 
DATA VISUALIZATION 
Looking onto the long tradition of 3D visualization, it is a 
surprise, there still exist a long list for the following topics for 
future research, not only in conjunction with 3D Laser Scanner 
data: 
(1) The optimum (synthetic) base length for virtual stereo 
mates as derived from Spatial Laser Scanner data. 
Due to practical requirements different results will appear; 
e.g., obviously there is a difference in the base length 
showing maximum deepness effect in opposite to the base 
length required for "natural" space perception. 
(2) The contribution of 3D Laser Scanner data for the 
generation of a lost or so far not existed stereo mate 
(3) The Geometric potential of (synthetic) stereo imagery; 
considering the effect of the so called stereoscopic 
exaggeration. 
(4) The use of Spatial Laser Scanner data in combination 
with historic stereo imagery, including the stereo 
Plasticon fund, see Figure 5. 
(5) The benefit of generating and combining day- and night 
stereo mates from Spatial Scanner data 
(6) The benefit of (synthetic) stereo panorama imagery; 
(7) The effect of different Pixel sizes for the stereo mates: 
(8) The visualization of wide range 3D Laser Scanner data; 
(9) The extension of the optical sharpness within a model, 
using different focal lengths for the stereo mates; 
(10) The simulation of the perception of the "natural" 
appearance of the object dimensions; 
(11) The Market potential for Spatial Laser Scanner data 
Figure 5. The use of Spatial Laser Scanner data in combination with historic stereo imagery, including the stereo Plasticon fund, 
with high responsibility must be evaluated, as proposed for, e.g., the Olympieion with the Acropolis and Parthenon and the 
Temple of Jupiter; Athens, Greece, a typical historic 19 th century H.C. White Co. Plasticon stereoview