# I used plot3. when I try to rotate the 3D image, it is too slow to rotate for each time.

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Houghton on 20 Aug 2015
Commented: Walter Roberson on 22 Aug 2015
hFig = figure('name','3D Plotting_Solve_Pyramid','numbertitle','off'); hold on;
set(gcf,'Renderer','OpenGL'); % might improve performance
hAxes = gca;
for row = 1:hightl
for col = 1:4:widthl
objcolor = double(I2(row,col,:))./255.0;
if objectpoint(row,col,3) >= -2.0 %&& (sum(objcolor)>0.3)
plot3(hAxes, objectpoint(row,col,1), objectpoint(row,col,2), objectpoint(row,col,3), '.', 'MarkerEdgeColor',objcolor);
end
end
end
%Set up the view.
xlabel(' X axis');
ylabel(' Y axis');
zlabel(' Z axis');
grid on;
cameratoolbar show;
axis vis3d;
axis equal;

Mike Garrity on 20 Aug 2015
Edited: Mike Garrity on 20 Aug 2015
I'm guessing that widthl and hightl are fairly large. This means that you're creating a large number of objects which are each drawing a single point. That's not a very efficient way to do it. You'll be much better off batching them up into a single object. A modern GPU is optimized for drawing large batches of geometry, not for drawing large numbers of tiny batches.
I discussed that in quite a bit of detail in this blog post and this blog post.
It looks like it'd actually be quite simple in this case. It's probably something like:
x = objectpoint(:,:,1);
y = objectpoint(:,:,2);
z = objectpoint(:,:,3);
r = double(x) / 255;
g = double(y) / 255;
b = double(z) / 255;
mask = (z(:)>=-2) & (r(:)+g(:)+b(:) > .3);
On my system, with a Quadro K600 on R2015a, that runs at over 10 million markers per second. You could probably do better with a bit of tweaking, but that's about 120 frames per second for this image:
Walter Roberson on 22 Aug 2015
"If S is empty, then the default size of 36 points squared is used."