Dynamic Stripes

Yellow centerline, solid plus 4' dashes

Earlier this year I wrote about highway stripes and perception. If you missed it, stop here and check out the article...interesting stuff! Today I want to talk about what it takes to draw all those little stripes in SketchUp. On the surface (no pun intended) it may seem like a repetitive and time-consuming task, but as usual, we have a few tricks up our sleeve.

On a flat model, we create the stripes as components, and then use the PathCopy plugin to string them along a welded path (which can be straight or curved). The technique is described near the end of this case study. A useful trick is to put the stripes in a separate group (all edges hidden) and float them an inch or two above the ground surface. This eliminates z-fighting, and makes it much easier to modify and show/hide as needed to explain different road configuration options. If you use shadows in your final exports, you'll want to uncheck "cast shadows" for this group so your stripes don't have shadows under them.

Working on terrain is harder. It's best to start by drawing all the striping on a flat plane, and then draping the line work onto a copy of the terrain mesh. Again, using a copy of the terrain allows us to isolate the stripes in a separate group floating just slightly above the ground.

A while back we did some work on a dynamic component that allows us to select from a variety of stripe configurations, which are automatically scaled to an appropriate length. It's not perfect (we see strange behavior sometimes) and it's not well-suited for extremely large models, as it generates many copies of hidden sub-components. However, it can be a big time-saver for quick conceptual studies. If you are interested in giving it a spin, please contact me, and I'll send a copy.


Joshua Cohen is a Principal at Fat Pencil Studio