Making an animated torus in gnuplot and gimp
The gnuplot
code in this article, creates several frames of a 3D
torus with a visible structural grid from different viewing angles, like the one in the image below.
[download id=”3549″]
In geometry, a torus (plural tori) is a surface of revolution generated by revolving a circle in three-dimensional space about an axis coplanar with the circle. If the axis of revolution does not touch the circle, the surface has a ring shape and is called a torus of revolution.
From Wikipedia https://en.wikipedia.org/wiki/Torus
By modifying the circles
and rings
variables in the script you can increase and decrease the number of circles and rings that appear on your torus
.
The above image was generated using 60 circles and 30 rings.
To better explain what a circle
and what a ring
is, please have a look at the following two examples.
The following torus has 10 circles and 30 rings.
The next one has 60 circles and 10 rings.
The last torus has 10 circles and 10 rings.
Using the script, you can also play around with the set view
command and the for loop
to change the number of frames that will be produced and what movement should the camera perform before printing.
[download id=”3549″]
set terminal pngcairo transparent enhanced font "arial,10" fontscale 1.0 size 700, 400 unset key unset border unset tics set dummy u, v circles=60 rings=30 set parametric set isosamples circles, rings set hidden3d back offset 1 trianglepattern 3 undefined 1 altdiagonal bentover set urange [ -pi : pi ] noreverse nowriteback set vrange [ -pi : pi ] noreverse nowriteback do for [i=1:360/circles] { set view 25, i, 1, 1 set output sprintf('game-of-life-torus.%03.0f.png', i) splot cos(u)+.5*cos(u)*cos(v),sin(u)+.5*sin(u)*cos(v),.5*sin(v) with lines }
[download id=”3549″]
Below, you can see two examples of animation we build together using the gimp
application.
Showing one frame at a time.
Accumulating all frames into one, until the loop is reset.
To create the animation we followed the next steps:
- Executed
gnuplot torus.gnuplot
to generated the frames. - Then we started the
gimp
and from the menuFile
we chose the optionOpen as layers...
(Ctrl
+Alt
+o
). - We selected all the images we wanted for our animation and pressed the
Open
button. - The
Layers - Brushes
window got populated by the new frames. Please note that window you can use that to change the order of the frames (which are now the layers). - Following, from the menu
File
we chose the optionExport As...
(Shift
+Ctrl
+E
), from the pop-up window we selected the type of the file to begif
and pressed theExport
button. - At the final pop-up window, we enabled the
As animation
checkbox, then at theFrame disposal where unspecified
dropdown menu we choseOne frame per layer (replace)
and hit theExport
button which produce the first animation in this article (two images up).