Lightmaps are very important part of game environment production in UDK. The quality of baked lighting and shadows in your map depend on it. Lightmaps determine how your models are lit, how they receive and cast shadows.
In the following 5-part series, I will go into depth about UDK Lightmaps. You will learn everything you ever wanted to know about lightmaps and how to make your Static Meshes light and shadow correctly.
Lightmaps is something I've had a lot of problems with. So, I set out to know as much as I could about them. The following series are my studies.
There are many important principles to keep in mind when you are creating lightmap UVs and lighting your custom game models. To give you a better example of what lightmaps actually do, here are a couple of screenshots.
In the first part of the series I will cover 18 important and tested principles of creating and using lightmaps for UDK. Consider this first tutorial as an introduction to Lightmaps. These principles are the key for making your static custom models light/shadow correctly.