Low Poly Vehicles
We often create large 3d models that include many copies of various components. For instance, the model we made for the Seattle Streetcar Expansion contains nearly 15,000 component instances. The Williams Bikeway model tips the scale at 30,000, split into three different files. When placing so many components, it is very important to strike a balance between simplicity and realism in order to manage file size. Many copies of a highly-detailed component can quickly bloat a model, making it frustrating to operate and prone to error. In an earlier post, we talked about this issue with regard to tree components. Here we’re going to deal with vehicles and heavy equipment.
Suppose you need to place some pickup trucks in your model. You might hunt around a bit and find this lovely model of a 2006 Toyota Tacoma, for example. Is that mud on the tires?! Wow!
This model would be killer for creating the scene for some sort of extreme off-road adventure, but, at 3.3 MB, it would be a mess to try to use many copies of it to populate a streetscape or a parking lot. So instead, we use what’s known as a “low-poly” component that looks like this:
A well-made, low polygon count model minimizes the file size of a model while maintaining the recognizability of the intended object. The pickup model above is a mere 82KB. That means the detailed Tacoma’s model carries 41 times more information than our truck. In other words, we could place 41 of our trucks along a street and the 3d redraw time would be the same as if we used just one detailed Tacoma.
Using simplified models isn’t only about managing megabytes and redraw time. It’s also about using the appropriate amount of detail to achieve a graphic goal. If the focus of the images is a street configuration, for instance, the viewer shouldn’t be distracted by decals on the windows of parked trucks. We want to evoke “any pickup” rather than “that particular pickup.”
That said, we got curious about how dimensions of the generic low-poly vehicles compared with specific models of cars and trucks, and created a chart. (click for larger view).
Our growing library of vehicle components includes a large selection of low-poly construction vehicles and equipment (and at least one high-poly component). Some were created from scratch, others were adapted from open source models downloaded from the SketchUp 3d Warehouse. Having a stable of components at the ready makes it much faster to illustrate construction logistics or streetscape scenes.