Moving point along a curve (3D-Animation plots)

I am trying to make an animation of the trajectory (circular orbit of 7000 km altitude) of a satellite orbiting the Earth. The following vectors x,y,z represents the coordinates of it (obtained integrating the acceleration due to the nonspherical gravitational potential) in the reference system.

   fh = figure('DoubleBuffer','on'); 
   ah = axes('Parent',fh,'Units','normalized','Position',[0 0 1 1],...
          'DataAspectRatio',[1 1 1],'DrawMode','fast');

    x = 1.0e+003 * [ 1.293687086462776 1.355010603320554  ...
           1.416226136451621    1.477328806662750    1.538313743926646...
           1.841302933101510    2.140623861743577    2.435680048370655...
           2.725883985836056    3.830393161542639    4.812047393962632...
           5.639553477924236    6.285935904692739    6.778445814703028...
           6.981534839226300    6.886918327688911    6.496619397538814...
           5.886899070860056    5.061708852126299    4.051251943168882...
           2.891621923700204    1.551975259009857    0.148687346809817...
          -1.259946709379085   -2.614876359324573   -3.789635985368149...
          -4.822735075152957   -5.675398819678173   -6.314344260262741...
          -6.725008970265510   -6.860046738669579   -6.714044347581475...
          -6.291232549137548   -5.646225528669501   -4.790489239458692...
          -3.756316068441812   -2.581710448683235   -1.257064527234605...
           0.118190083177733    1.488198207705392    2.797262268588749...
           3.943218990855596    4.943060241667732    5.760107224604901...
           6.363435161221018    6.741208871652011    6.844507242544970...
           6.669637491855506    6.222229021788314    5.549112743364572...
           4.665587166679964    3.605338508383659    2.407805301565781...
           1.076891826523990   -0.297413079432155   -1.658804233546807...
          -2.950960371016551   -4.105336427038419   -5.093651475630134...
          -5.875676956725480   -6.417825276834068   -6.694317613708315...
          -6.702354075060146   -6.441476385534835   -5.920328191821120...
          -5.149356931765655   -4.165756794143557   -3.010476122311884...
          -1.730623521107957   -0.547981318845428    0.651933236927557...
           1.830754553013015    2.950797411065132];
        y = 1.0e+003 *[   -6.879416537989226   -6.867600717396513...
          -6.855237614338527   -6.842328214064634   -6.828873545169439...
          -6.753459997528374   -6.664593892931937   -6.562452270514113...
          -6.447238135027323   -5.857768973060929   -5.080802144227667...
          -4.141502963266585   -3.069449548231363   -1.712593819793112...
          -0.283073212084787    1.157789207734001    2.547934226666446...
           3.733185664633135    4.781256997101091    5.653507474532885...
           6.316540958291930    6.760480121739906    6.924451844039825...
           6.801366712306432    6.393950562012035    5.763652137956600...
           4.918852380803697    3.890903548710424    2.717191733101876...
           1.385839187748386   -0.001786735280855   -1.388680800030854...
          -2.717513794724399   -3.877348086956174   -4.892062889940518...
          -5.723943344458780   -6.341064412332522   -6.729295147896739...
          -6.844976271597333   -6.684181367561298   -6.252308741323985...
          -5.600523241569850   -4.741636145151388   -3.707934368103928...
          -2.537101251915556   -1.208445066639178    0.169057351189467...
           1.539102816836380    2.845512534980855    3.993289528709769...
           4.989150886098799    5.795183343929699    6.379362665363127...
           6.723976759736427    6.794165677259719    6.586864956951024...
           6.108394444576384    5.387403581100790    4.449452017586583...
           3.332306147336086    2.080126804848620    0.757432563194591...
          -0.595089763589023   -1.923045482863719   -3.172486599444496...
          -4.302442851663575   -5.254127434062967   -5.988250483410006...
          -6.472859710456819   -6.675113607083117   -6.664054266658221...
          -6.440275312105615   -6.010308893159839];
        z = [ -1.348762314964606   -1.416465504571016   -1.484053975854905...
          -1.551522350691171   -1.618865254528658   -1.953510294130345...
          -2.284215283426580   -2.610320163346533   -2.931177500785390...
          -4.153679292291825   -5.242464339076090   -6.162825517200489...
          -6.884797354552217   -7.440577139596716   -7.680358197465111...
          -7.594616346122523   -7.183952381870657   -6.529293328494871...
          -5.637062917332294   -4.540678277777376   -3.279180600545935...
          -1.817413221203883   -0.280548741687378    1.268253040429052...
           2.764251377698321    4.066975661566477    5.218214283582148...
           6.174673504642019    6.899157495671121    7.375688520371054...
           7.548875108319217    7.410793523141250    6.965068314483629...
           6.271309946313485    5.343254095742233    4.215431448848456...
           2.928028129903598    1.469574073877195   -0.048649548535536...
          -1.563638474934283   -3.013536101911645   -4.285161526803897...
          -5.397128342069014   -6.308837263463213   -6.985946890567337...
          -7.415475222950275   -7.542406523585701   -7.363021555333582...
          -6.884639818710263   -6.158276823110702   -5.199186592259776...
          -4.043958234344444   -2.736923814690622   -1.283388986878655...
           0.219908617803070    1.712828428793243    3.135072606759898...
           4.411790351254605    5.510842969067953    6.387336537361380...
           7.004133661144990    7.332163450286972    7.366696289243980...
           7.105258174916579    6.555393588532904    5.727091807637045...
           4.660073989309112    3.399622357708514    1.999243120787114...
           0.701744421660999   -0.620073499615723   -1.923270654698332...
          -3.164705887374677 ]; 
      load('topo.mat','topo','topomap1');
      [x1,y1,z1] = sphere(50);
      x1 = 6678.14*x1;
      y1 = 6678.14*y1;
      z1 = 6678.14*z1;
      props.AmbientStrength = 0.1;
      props.DiffuseStrength = 1;
      props.SpecularColorReflectance = .5;
      props.SpecularExponent = 20;
      props.SpecularStrength = 1;
      props.FaceColor= 'texture';
      props.EdgeColor = 'none';
      props.FaceLighting = 'phong';
      props.Cdata = topo;
      surface(x1,y1,z1,props);
      light('position',[-1 0 1]);
      light('position',[-1.5 0.5 -0.5], 'color', [.6 .2 .2]);
      view(3);
      handles.p1 = line('parent',ah,'XData',x(1),'YData',y(1),'ZData',...
          z(1),'Color','red','LineWidth',2);
      handles.p2 = line('parent',ah,'XData',x(end),'YData',y(end),...
          'ZData',z(end),'Marker','o','MarkerSize',6,'MarkerFaceColor','b');
      oaxes([0 0 0],'Arrow','extend','AxisLabelLocation','side',...
          'Xcolor','green','Ycolor','green','Zcolor','green');
      axis vis3d equal;
      handles.XLim = get(gca,'XLim');
      handles.YLim = get(gca,'YLim');
      handles.ZLim = get(gca,'ZLim');
      set([handles.p1,handles.p2],'Visible','off');
      xmin = handles.XLim(1);
      ymin = handles.YLim(1);
      zmin = handles.ZLim(1);
      xmax = handles.XLim(2);
      ymax = handles.YLim(2);
      zmax = handles.ZLim(2);
      set(ah, 'XLim', [xmin xmax],'YLim', [ymin ymax],'Zlim',[zmin zmax]);
      view(3);
      handles.hsat = line('parent',ah,'XData',x(1), 'YData',y(1),...
          'ZData',z(1),'Marker','o', 'MarkerSize',6,'MarkerFaceColor','b');
      k = uint8(2);
      u2 = uint8(length(x));
      while k<u2
        handles.htray(k) = line([x(k-1) x(k)],[y(k-1) y(k)],[z(k-1) z(k)],...
         开发者_StackOverflow社区   'Color','red','LineWidth',3); 
        set(handles.hsat,'XData',x(k),'YData',y(k),'ZData',z(k));
        drawnow;
        k = k + 1;
    end

where oaxes is a FEX application that allows getting an axes located (in this case) at the origin (0,0,0) of the PlotBox.

I have read the User Guide's Graphics section in the Matlab Help Browser. It recommends to use low-level functions for speeding the graphics output (this is the reason for which I use the line function instead of plot3) and the renderer painters for line graphics. In my case, I can not use it because I have a surface (the Earth) which is not well drawn by it. I want to get something similar to this (I have tried to get in touch with the author but I have not got response). The final result is a slow (it takes 11.4 seconds in my computer with microprocessor intel core i5) and discontinuous animation (perhaps I need more points to get the blue point's movement looks like continuous but the integrator's output points are invariable). I would like to know what I should make to improve it. Thank you for your attention. Cheers.

A couple of things here.

1. DrawMode=fast probably doesn't do what you think it does. It's turning off depthsorting. I think that you really want depthsorting here.
2. You're creating line objects in the inner loop. You really want create a small number of graphics objects and reuse them. Could you create a single line object and set the XData, YData, & ZData, in the loop?
3. You can use hgtransform to avoid modifying the coordinates of hsat (as described here), but that would only make a difference if hsat was much more complex. I don't think it would buy you anything in this case.
4. You could reduce the resolution of your surface.
5. You probably want to set the figure's Renderer property to OpenGL.

In this case, but I'm getting almost 20 frames per second on my system with your code. After making those changes, I'm getting about 100 frames per second. What sort of framerate are you shooting for here?

I believe the main reason your animation is slow is because you are using the Phong lighting algorithm which is computationally expensive. To see the effect it has on performance, try specifying Gouraud shading instead:

%#lighting('gouraud');
props.FaceLighting = 'gouraud';    %# faster interpolating method