Steel Bridge Animation

Steel Bridge Animation

Recently I wrote about a model I made of Portland’s Steel Bridge. The post featured a slideshow of the bridge at different stages in its lift process, and at the time I hadn’t yet fully animated it. I’ve had the opportunity since then to experiment with a couple of different plugins for SketchUp and was able to produce a video of the Steel Bridge…in motion! 


View of the raised bridge from the Eastbank Esplanade

View from the Eastbank Esplanade of the raised lower deck.

The final was produced using a combination of SketchUp plugins and a screen-capture program that recorded the animation playing in SketchUp. The first plugin I used was Fredo6’s Animator, available on Though still in Beta (check it out!), it’s been our go-to plugin for animating our models because it gives users an incredible amount of control. However, the scaling function has yet to be fully developed and I needed a way to show the cables “elongating” as the counterweights lowered to pull the bridge decks up.

My next step was to look for another plugin that could accomplish the animated scaling. I happened upon Keyframe Animation by Regular Polygon as a potential solution. It provided a much simplified user interface than Animator, though complexity comes back in how one manages scenes and camera views while recording movements in the model. It was still relatively simple setting up the animation itself, though there was a catch in getting my animation out of SketchUp (and onto your screens). Keyframe currently has no way of simply exporting a movie file directly from SketchUp on a Mac, so I had to find another way. The solution was to run a screen capture program called iShowU while the animation was running, and saving the (.mov) file from there. In the end I learned quite a bit about animating with SketchUp, and became familiar with several plugins, programs, and workarounds in the process.

And now, ladies and gentlemen, for your viewing enjoyment: the animated Steel Bridge:



Also, here’s a video my studiomate, Yelena, took while she was biking across the bridge:


About Jannine Hanczarek

Jannine Hanczarek is a Technical Illustrator at Fat Pencil Studio.
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