3D animation of imported data

I'm trying to animate a 16 x 16 pressure map. The pressure data are imported as num_frames * 16 by 16 array. I reshape it to a 16 by 16 by num_frames array, and use "surf" to display it. I have two problems. I want to be able to rotate the view in real time, but I can't work out how to do that. The animation runs OK without messing with the azimuth and elevation, but when I add the azimuth and elevation I get "too many output arguments" with the "[az, el] = view" line.

P = permute(reshape(out', 16, 16,[]),[2,1,3]);
clearvars out

dims = size(P)
num_frames = dims(3)

[az, el] = deal(-30, 30)    % initial view direction
for frame = 1:num_frames
    surf(P(:, :, frame))
    view = [az, el]
    axis([1 16 1 16 0 max(max(max(P)))])
    [az, el] = view         %update view direction
    pause(0.05)
end

The other problem is that I need the "pause" command for it to animate(without the [az, el] stuff. Is it just running too fast without the pause? How to I correctly synchronize the rendering to the monitor display rate?

Thanks

[Peter Fraser]

Fixed it.

[az, el] = deal(-30, 30)    % initial view direction
for frame = 1:num_frames
    surf(P(:, :, frame));
    view([az, el]);
    axis([1 16 1 16 0 max(max(max(P)))]);
    pause(0.03)
    [az, el] = view         %update view direction

end

There were two problems. My syntax for setting the view azimuth and elevation was wrong. Also, I need to get the az and el after the pause. If I execute

[az, el] = view

before the pause it returns the old value most of the time.

I still need to understand the synchronization issues. Why do I need a pause to get the animation to run in the first place, and how long do I need to wait before the [az, el] = view command? Is there some sort of "wait for frame to be displayed" command?

Answer 1

[Nut]

Hi,

I'm not able to answer your question, I'm writing just for a suggestion. I never used the "drawnow" function, but I know that it is often used when an animation is needed. So, I think it may be helpful for you, try to read about it:

http://it.mathworks.com/help/matlab/ref/drawnow.html

[Peter Fraser]

Thanks. That looks interesting and appropriate. I'll check it out.