Question

I am trying to animate a 3d mesh that chnages over time using trimesh. On each iteration I draw the mesh. On some iterations I also change the camera position orientation etc. However the camera resets after plotting. I would like the camera position to stay fixed on further iterations. How can I do that?

Answer 1

If you do a clf or cla anywhere, that also clears the axes’ camera* properties. You’ll have to save those and re-set them on every iteration:

g = [];
while ~done

    clf;

    ... %# generate mesh and other elements

    %# set previous Camera* properties
    if ~isempty(g)
        set(gca, g); end

    %# possibly adjust them for the current frame
    ...

    %# save all Camera* properties
    g.CameraPosition     = get(gca, 'CameraPosition');  
    g.CameraTarget       = get(gca, 'CameraTarget');    
    g.CameraUpVector     = get(gca, 'CameraUpVector');
    g.CameraUpVectorMode = get(gca, 'CameraUpVectorMode');
    g.CameraViewAngle    = get(gca, 'CameraViewAngle');

    %# Grab the current frame
    ...

end

Alternatively, you can save handles to all objects your create, and delete them on each iteration. AFAIK, this will preserve the axes’ properties:

while ~done

    h(1) = trimesh(...)
    h(2) = patch(...)
    ...

    %# grab the frame
    ...

    %# delete all plot elements instead of clf/cla
    delete(h)

end

Haven’t tested this last one though, so you might want to do some experimenting with that first.