Texture Usage in Materials
Generally speaking when utilizing Textures inside of your Materials meant for mobile devices, you should try and use a few Texture as possible. This will help reduce the memory footprint of your project and will also help cut down on the amount of Textures fetches that are needed. Generally speaking, most opaque (non-transparent) Materials that have only one layer should only need the Base Color, Roughness, and Normal inputs to come from Textures. All other inputs like Metallic should use Constant's Material Expression nodes. The image below shows how the Textures used in the M_Metal_Steel Material that can be found with the Mobile Starter content have been setup.
Most Materials that only have one layer like the Material shown above, should have their Textures setup in the following manner as it only requires two Textures:
- Texture 1
- BaseColor in RGB.
- Roughness in Alpha Channel.
- Compression set to Default (DXT 1/5, BC1/3 on DX11).
- Texture 2
- Normal map in RGB
- Compression set to Normalmap (DXT5, BC5 on DX11) .