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#
8.3 Orbiting a static map

Our third animation keeps a fixed gridded data set but moves the camera angle around the full 360°. We use grdview to generate a shaded-relief image sequence using the new enhanced -E option. No additional information is plotted on the image. As before we produce an animated GIF image and a simple HTML wrapper for it.

    #!/bin/sh
    #               GMT ANIMATION 03
    #
    # Purpose:      Make web page with simple animated GIF of Iceland topo
    # GMT progs:    gmtset, gmtmath, psbasemap, pstext, psxy, ps2raster
    # Unix progs:   awk, mkdir, rm, mv, echo, convert, cat
    #
    # 1. Initialization
    # 1a) Assign movie parameters
    . gmt_shell_functions.sh
    lon=-20
    lat=65
    dpi=100
    x0=1.5
    y0=0.75
    px=4
    py=2.5
    el=35
    az=0
    name=`basename $0 '.sh'`
    mkdir -p $$
    gmtset DOTS_PR_INCH $dpi
    frame=0
    grdclip -Sb0/-1 -G$$_above.nc Iceland.nc
    grdgradient -M -A45 -Nt1 $$_above.nc -G$$.nc
    makecpt -Crelief -Z > $$.cpt
    while [ $az -lt 360 ]; do
            file=`gmt_set_framename $name $frame`
            if [ $# -eq 0 ]; then   # If a single frame is requested we pick this view
                    az=135
            fi
            grdview $$_above.nc -JM2.5 -C$$.cpt -Qi$dpi -B5g10/5g5 -E$az/${el}+w$lon/${lat}+v$x0/$y0 -P -X0.5i -Y0.5i --PAPER_MEDIA=Custom_${px}ix${py}i > $$.ps
            if [ $# -eq 0 ]; then
                    mv $$.ps $name.ps
                    gmt_cleanup .gmt
                    gmt_abort "$0: First frame plotted to $name.ps"
            fi
            ps2raster $$.ps -Tt -E$dpi
            mv $$.tif $$/$file.tif
            az=`expr $az + 5`
            echo "Frame $file completed"
            frame=`gmt_set_framenext $frame`
    done
    convert -delay 10 -loop 0 $$/*.tif $name.gif
    cat << END > $name.html
    <HTML>
    <TITLE>GMT 3-D perspective of Iceland</TITLE>
    <BODY bgcolor="#ffffff">
    <CENTER>
    <H1>GMT 3-D perspective of Iceland</H1>
    <IMG src="$name.gif" border=1>
    </CENTER>
    <HR>
    Here we show ETOPO2 topography of Iceland as we move the view
    point around the island.
    <I>$name.sh: Created by $USER on `date`</I>
    </BODY>
    </HTML>
    END
    # 4. Clean up temporary files
    gmtset DOTS_PR_INCH 300
    gmt_cleanup .gmt

Figure 8.3: Orbiting a static map.

Next: 8.4 Flying over topography Up: 8. Creating GMT Animations Previous: 8.2 Examining DEMs using Contents Index