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Comment by yaddayadda | Hacker News Reader

I love this, as well as the sister-site, 507 Mechanical Movements [1].

I'm surprised at how laborious the process is [2]. Is there not a way to automate this in a CAD program and export it (e.g. SolidWorks [3]); or is that limited to video, not a more interactive simulation? Are there any open source CAD programs that would support generation of such simulations?

[1] http://507movements.com/

[2] http://www.animatedengines.com/howto.html

[3] http://www.solidworks.com/sw/products/3d-cad/cad-animation.h...

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507 Mechanical Movements has animations with canvas that seem to have a higher frame rate than the animated GIFs on this site. However, all those diagrams are something that SVG would be a perfect fit for and you can actually animate SVG in a more natural way by saying »This object should rotate« or »this object should move there« instead of drawing every frame by hand (with the occasional pixel errors). Plus, it'd be vector graphics.

(Edit: Just read the explanation how they do it, and notice that even the CAD program doesn't make it any easier, if they have to manipulate everything by hand, but at least the SVG process would be pretty much identical while allowing for arbitrary framerates and higher quality output.)

I was rather disappointed to see that they were animated gifs. I would much rather see them in a format where you can run them with independent speeds and framerates.

I figure it would be better to represent the image as a bunch of shapes with changing position/rotation. In fact using these animations as a base It might not be too hard to automate the process to identify the shapes and the connections between them.

Given that the site has been around since the year 2000, assuming the images haven't changed, the tools widely available / understood at that were rather limited when compared with today.

At least on the site liked in the OP they are sprite maps* saved in gif format not animated gifs.

For example: http://www.animatedengines.com/jets.html

The custom player takes the class of the div container (http://www.animatedengines.com/img/tprop_fl.gif) "aeplayer aepframes_6" to determine the number of frames (6) and offsets the background-position vertically for each frame by the amount of the individual frame height which equals the div container height, thus appearing animated.

*see this example with a sprite map in png format http://jsfiddle.net/simurai/CGmCe/

Sketchup has animation built in and is trivially scriptable in Ruby. Interactive controls are created in HTML/JS. It's not open source, but it doesn't cost anything for the regular version.

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