In Chapter 1, SDK Game Development Hub, we used Terrain Editor to manually create a heightmap and Scene Composer to put things together into scenes. Those were the two ways of creating worlds in jMonkeyEngine. In this chapter, we'll look into creating worlds using code or procedural generation. This can often be very quickly set up, but getting it right (and performant) can be tricky. To achieve this, we will make use of techniques such as custom meshes and batching. Batching is a method of taking several geometries using the same Material instance and creating one mesh out of all their meshes. This can significantly improve the performance of the application.