Disable sRGB on Metallic Textures

When importing a metallic texture file into Unity, it's important to disable sRGB. The main reason for this is how Unity, and most game engines, interpret texture information.

The color information in most image files is stored in sRGB (standard Red Green Blue) color space, which is a non-linear color space. That means, the changes in color are not evenly distributed across the range of values from 0 to 255. This non-linearity is good for storing colored images because it closely matches the way human eyes perceive light and color.

However, non-color data such as metallic, roughness, or normal map textures should be read in a linear color space. These values are not meant to be colors per se, but rather, they represent data like how rough or smooth a surface is, or how metallic it appears.

If you don't disable sRGB for these textures, Unity will apply a gamma correction to them, leading to incorrect rendering because the engine will be interpreting the data as if it's a standard color texture. This can lead to your materials not behaving as expected, making your metallic surfaces appear too glossy or too dull, for example.

Therefore, for any textures that represent non-color data, you should ensure sRGB is turned off in the import settings in Unity.

– ChatGPT4 - 2023.05.16