The purpose of this post is to serve as a helpful guide for fellow 3D artists who encounter challenges while creating textures in software like Photoshop or Blender. It aims to address the confusion that arises from understanding how white and black values impact various texture types. I will begin with the basics and gradually delve into more intricate aspects.
- White: Rough, matte, not glossy, non-reflective
- Black: Glossy, shiny, sleek, not rough, reflective
- White: Metal, raw metal
- Black: Non-Metal
Ambient Occlusion Map
- Black: No ambient light received
- White: Areas that receive ambient light fully
There are other textures, such as displacement/bump maps using black & white values, but the methods used to create such maps are straightforward. Therefore, I don’t see an explanation being necessary in that regard. Instead, I want to discuss how an ambient occlusion texture works and what it is in the first place. Many mistakes are made when creating such a texture in Photoshop and related software.
What’s purpose of ambient occlusion texture?
Its purpose to simulate the way ambient light interacts with the surfaces of objects to create soft shadows and shading effects, which adds depth and detail to the overall scene.
What is ambient light then?
The term ambient light refers to the overall level of light present in the scene that comes from all directions. In the real world, ambient light can come from various sources, such as sunlight, moonlight, or light scattered and reflected from surfaces in the environment. It is the light that fills the environment and provides a baseline level of illumination, even in areas that are not directly lit by any particular light source.
Other usage cases and why we need soft shadows in the first place
The main idea is to create a consistent scenery, similar to how we bake our high-poly mesh to low-poly and use a normal map to achieve visually appealing fake details. AO maps do the same thing, but with the light. In other words, ambient light prevents a scene from appearing completely dark in shadowed and unlit areas, making it more visually appealing and avoiding harsh, unrealistic shadows.
To give an example, imagine a scene where objects are close together, blocking light from reaching certain parts of the environment. We know that users will interact with these parts or they will be prominent in a render, so we don’t want them to stand out harshly. Without AO maps, these areas of the environment or the object might appear completely black or have very harsh shadows, due to the lack of illumination blocked by the objects mentioned above. By applying ambient occlusion to a 3D model, the rendering engine can introduce subtle shadows and darkening to areas that would naturally receive less light. This approach enhances the realism of the object within the scene, providing a grounded and convincing appearance.