Computer graphics uses flat triangles to approximate smooth surfaces, but if you're willing to allow triangles to bend a bit, then you can build any surface by gluing enough of them together.

But for more complex shapes, triangles are better -- what are called polygons in 3D graphics. Look at this beautiful teapot made out of polygons. A collection of polygons like this is a mesh.

The mesh is like a papier-mâché model of a 3D shape built from triangles. With it, developers can modify an object to fit their creative vision. Materials are 2D textures overlaid on the 3D ...