Difference between revisions of "Hardware 3D (C++ DirectX Graphics) Tutorial 34"
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| − | Normal mapping is like what texture mapping would be if it actually lived up to its name. Time to learn about tangent space | + | Normal mapping is like what texture mapping would be if it actually lived up to its name. Time to learn about tangent space and other such weird things, I guess. |
== Topics Covered == | == Topics Covered == | ||
| Line 6: | Line 6: | ||
* Texture alignment | * Texture alignment | ||
* RGB encoding of normal vectors | * RGB encoding of normal vectors | ||
| + | === Part 2 === | ||
| + | * Translation of object space normal map into view space | ||
| + | * Refactoring using SOLID principles | ||
| + | ** Single Responsibility Principle | ||
| + | ** Open / Closed Principle | ||
| + | * Definition and limitations of object space normal mapping | ||
| + | === Part 3 === | ||
| + | * Tangent Space | ||
| + | * Extraction of Tangent and Bitangent vectors from vertex data (pos, normal, uv) | ||
| + | * Synthesis of TBN matrix (tangent space rotation matrix) | ||
| + | * Fixing the mapping from Green color channel => Z component of normal map vector | ||
| + | |||
| + | == <span style="color:red">Errata</span> == | ||
| + | In '''Part 1''', Chili decodes the z component of the normal map by mapping from 0..1 => 0..1 directly, but this mapping is not common, nor is it correct for the map we are using. All channels should be mapped with 0..1 => -1..+1. This will be corrected in '''Part 3'''. It ''is'' true that the z channel will never be less than zero in a proper (tangent space) normal map, but it does ''not'' seem to be common to use this unused range to expand the dynamic range of the z channel encoding. | ||
== Video Timestamp Index == | == Video Timestamp Index == | ||
| − | * [https://youtu.be/ | + | * [https://youtu.be/1aaAyL6SyE0 Tutorial 34 - Part 1] |
| + | * [https://youtu.be/Tf2ZOyc0XcQ Tutorial 34 - Part 2] | ||
| + | * [https://youtu.be/PnazRFnPPcg Tutorial 34 - Part 3] | ||
== Source Code == | == Source Code == | ||
Latest revision as of 19:13, 14 September 2019
Normal mapping is like what texture mapping would be if it actually lived up to its name. Time to learn about tangent space and other such weird things, I guess.
Contents
Topics Covered
Part 1
- Normal mapping motivation / goal
- Texture alignment
- RGB encoding of normal vectors
Part 2
- Translation of object space normal map into view space
- Refactoring using SOLID principles
- Single Responsibility Principle
- Open / Closed Principle
- Definition and limitations of object space normal mapping
Part 3
- Tangent Space
- Extraction of Tangent and Bitangent vectors from vertex data (pos, normal, uv)
- Synthesis of TBN matrix (tangent space rotation matrix)
- Fixing the mapping from Green color channel => Z component of normal map vector
Errata
In Part 1, Chili decodes the z component of the normal map by mapping from 0..1 => 0..1 directly, but this mapping is not common, nor is it correct for the map we are using. All channels should be mapped with 0..1 => -1..+1. This will be corrected in Part 3. It is true that the z channel will never be less than zero in a proper (tangent space) normal map, but it does not seem to be common to use this unused range to expand the dynamic range of the z channel encoding.
