【GraphicsTier】
1、enum GraphicsTier
2、enum ShaderQuality
3、enum BuildTargetGroup
4、EditorGraphicsSettings.SetTierSettings
public static void SetTierSettings(BuildTargetGroup target, Rendering.GraphicsTier tier, Rendering.TierSettings settings);
Please note that if PlatformShaderSettings set to different tiers are not identical, then tier variants will be generated for the shader even if #pragma hardware_tier_variants is missing.
5、Shader Hardware Variants
To enable the generation of shader hardware variants, add #pragma hardware_tier_variants renderer, where renderer is one of the available renderering platforms:
参考：
1、https://docs.unity3d.com/ScriptReference/Rendering.GraphicsTier.html