I do almost all my physical designs in OpenSCAD, and sometimes I want to post an image of my models. Since these are 3D models we’re talking about, a static image is kinda insufficient, but an animated GIF can do the job nicely.
OpenSCAD has an animation feature which allows you to create models that can mutate relative to time. While it’s primitive, it lets you slap a time-based rotate around your top-level object to get a nice 360 spin view. Then, when you select Animate from the View menu, the display will animate.
To go from the animated view in OpenSCAD to an animated GIF, check the “Dump Images” checkbox in the animation controls. This will cause each frame to be written out to a PNG file in the same directory as the .scad file. I like to check the box and then wait for the animation to repeat a little more than once to be sure that all the images have been dumped.
Once all the images are on disk, converting them into an animated GIF is surprisingly simple if you have ImageMagick’s convert utility. Here’s the command I use to convert a bunch of frames into an animated GIF:
|convert 'frame*.png' -set delay 1x24 animated.gif|
The only real gotcha here is the “-set delay” option, which has a cryptic syntax: NxM means “N units of 1 second divided by M”. Thus, “1×24” means 1/24 of a second. I’ve had the most success setting the frame delay this way, but there are probably other ways to do it.