Animation Optimisation

I had run into issues with the line animations running at a low frame rate in Processing (circa 16 fps) once I upped the output size to 1920 x 1080 pixels. Having spent some time reading around, I initially tried rendering the animation using Open GL but with no real performance gain in exchange for a loss in line draw quality. Subsequently I tried re-writing the various nested for loops as while loops and then ran them backwards eg

int i = len;
while(--len >= 0){
// do something

in favour of

for(int i = 0; i < len; i++){
// do something

This change made a marginal improvement.

I then tried removing some of the vectors supplied to the drawLine method, ie reducing the cross-hatching to single directional hatching. This made a noticeable improvement thus I realised that draw commands are relatively ‘expensive’ in Processing, as in many other languages.

Because I wanted the view of the noise lines to be close enough not to notice the edges of the distorted plane they belong to, I knew that some of the lines were being drawn off screen, thus effectively wasting valuable CPU and reducing frame rate. Looking around the Processing reference I found a couple of methods that take a vertex (ie nominal x, y, z data) and return an actual x or y value (screenX(), screenY()). Using these methods I set up a validity test which ensures only lines which begin within the visible area are actually draw.

The result is a huge improvement – not only have I pushed fps up to 30+, noise settings that previously resulted in unusable animations due to clipping or CPU meltdown are now possible.

Take a look at this full size capture.

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