Pyramids

Here’s an interesting picture taken as the result of some accidental aerobatics in the Cannery area. If your point of view is under the water, you can see that all of the wooden pillars on which the piers stand are actually much longer than you can see from above the surface, and come to a point at some great depth. In other words, they are not square posts at all but inverted square-based pyramids.

The reason things are done this way is to save on rendering resources in your client machine, where the basic unit of cost is often the simple triangle. A square post of any height has two triangles per face, so a total of 12 triangles in all. A square-based pyramid, on the other hand, has two triangles on the base (the top of the post in this case), one triangle per side and of course no bottom face at all. This gives a total of only 6 triangles, a saving of 50%. The extremely elongated pyramids still look like square posts if you only look at the portion above the surface.