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snap3dv - create ascii file for 3D viewing from a snapshot
in=snapshot_file out=ascii_file [parameters=values...]
prepares an ascii file in some "3d" format (see MODE below) for viewing
with some of the available interactive 3D display tools that are available
under MSDOS, SunWindows and X-windows.
Three viewing coordinates must be
selected, any general bodytrans(5NEMO)
variable can be choosen, though
generally x, y and z will suffice. A bounding box around the particles can
be drawn, a different cube can be selected, but particles outside the cube
are not visible. Each particle can be given its own color, based on an
integer bodytrans function (the actual color on the screen wil depend on
your device driver and hardware). Lastly, any subset of particles can be
choosen for display using a visibility (0 or non-0) integer bodytrans function.
For display tools that support the multiple layer concept, the non-zero
value of the visibility is used to identify its layer. This often means
that the form of the color and visib keywords are rather similar; for example,
The following parameters are recognized in any order if the keyword
is also given:
The ViewWld is
a Suntools program, and accepts a list of vectors and/or points. The first
3 columns are the X,Y and Z positions. The 4th column is an integer denoting
move(0), draw line(1)
or draw point(2)
The 3DV format is a free
format ascii listing consisting of two parts. For each part the first line
consists of an integer denoting how many data lines this part consists
of (excluding that header line). This first part defines the X,Y,Z positions
of N points in 3D space:
- Input data file, must be in standard snapshot(5NEMO)
format [No default].
- The value of x-expression is plotted
along the X axis. x-expression is a real-valued C language expression over
the real values x, y, z, vx, vy, vz, phi, t, and the integer value i. The
default is x.
- See above. The default is y.
- See above. The default is z.
- Range of values for the X
axis, specified either as a single number (in which case the lower bound
is zero) or a pair of numbers separated by a colon or none, if the program
is to use autoscaling. The default range is autoscaling.
- See above. The default is autoscaling.
- See above. The default
- Only the first plot frame with the correct time
value will be selected for output. The default is the first frame in a
- Determines the visibility of particles. expression
is a integer expression in the above variables; only points with non-zero
values are plotted. The default is 1.
- Determines the point
color. expression is an integer expression in the above variables; colors
depend on your device driver/hardware. The default is 10.
- Color of the border if to be plotted. set color to -1 if no border is requested.
- Floating point format with which the X,Y,Z coordinates are
plotted. Although the default format (%f) is general, one can generally
find a format which produced a more compact file format. [Default: %f]
- Output mode. Select any of the supported formats described in more detail
below: 3dv, x3d, acd, wld or dcx. [Default: 3dv].
X1 Y1 Z2
X2 Y2 Z2
XN YN ZN
The second part consists of the drawing operations, now referring to the
points by their index number (1 being the first one). The point index number
is in the first column; if the second column is 0, it means a move (with
no color), for a non-zero number it is a draw to that next point with a
color as specified by by that integer. It will depend on your hardware what
the color is. Again, the first line in this part consists of an integer
how many "line-segments" will follow.
For example, to draw N points withouth
connecting lines, each point needs 2 segments:
NOTE: the 3dv program can only handle 1500 or so stars. It then quickly
runs out of memory. (an old 1988 version of the program was tested for this)
The X3D format is used by a public domain program x3d. It is a
simple ascii file, with 3 sections. The first section is one line, containing
2 integers: number of points, and number of segments. The next two sections
are the points and the segments. Points have 3 real coordinates, segments
two integers, describing which two points are to be connected.
X1 Y1 Z1
AcroSpin(tm) format can be written in a very compact way: 5 columns
with resp. X, Y, Z, Color and Layer, with a one line header describing its
Pointlist X Y Z Color Layer
X1 Y1 Z1 C1 L1
X2 Y2 Z2 C2 L2
Note that the total number of particles is not needed in this format.
This (binary) format is used by programs such as AutoCAD(tm). We do not
support it, but the MSDOS program ACROTRAN can translate such files into
A new popular 3D Studio dataformat (not implemented
ftp://dpls.dacc.wisc.edu/graphics/x3d/ x3d.2.2.tar.Z (28-jun-94)
http://hpux.asknet.de/hppd/hpux/X11/Viewers/x3d-2.2/ newer (tested 2003)
http://lib3ds.sourceforge.net/ 3D Studio File Format
26-sep-91 V0.0: created for MSDOS PJT
9-oct-91 V1.0: adapted for NEMO to read snapshots instead PJT
10-oct-91 V1.0a: added the ACD format PJT
11-oct-91 V1.0b: added WLD format PJT
8-sep-95 V1.0c: added X3D format PJT
10-jan-96 V1.0d: upgraded for new X3D (V2.2) format PJT
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