Total Baker Documentation

About texture baking


This section covers some common topics about Texture Baking. If you are already a baking expert you can skip it, otherwise you may find these basic notions useful to understand the secrets of baking. Here are some external links where you can learn more about baking:

Polycount - Texture Baking
Blenderartists - What is Texture Baking?
Pluralsight - Tips for Creating Perfect Normal Maps Every Time
CG Cookie - Big Idea: "Baking"

What is Texture Baking?

Texture Baking is the process of storing some characteristics of a model into a texture.
For example, it's possible to bake surface details into a Normal Map, or colors into a Diffuse Map. The main goal of this technique is to transfer details from a complex model to a simpler model that will be used in a scene.

How does it work?

Let's suppose that you want to bake a Normal Map by transferring surface details from a model to another. The main idea is that it's possible to find the differences between the two surfaces for each point and write this information into a texture. The way Total Baker does this is represented in the following scheme:

Let L be the lowpoly model and H the high-poly model. The baking algorithm needs to cast some rays from L to H in order to make a point-to-point match between their surfaces, so it is necessary for L to contain each point of H like a shell. Generally, a slightly enlarged version of L (named Cage) is used instead of L in the baking process. Note that a ray's direction corresponds to the normal of H's surface in the ray's origin.

The cage

A good cage can dramatically increase the quality of the baked textures. Its shape should follow as much as possible the high-poly's one and its UV Map shouldn't contain overlapped triangles. Here's an example of a cage positioned around a high-poly model:

The cage should also have the same UV Map of L, in order to get baked textures that fit well on L, too. Fortunately, Total Baker can automatically generate a cage from L expanding its vertices by a given offset while preserving the UV coordinates. Another important thing about cages is that depending by their surface smoothing, they may produce better or worse results. Looking at the following image it's possible to see that cages with unsmoothed (flat) normals can make some rays intersect wrong points on the high-poly geometry. This normally happens when the origins of two rays are very close but lie on different polygons.