ProceduralMaterial を Immutable でレンダリングし、メモリの使用容量を減らすために基になるデータをリリースします。
'Freezing' a ProceduralMaterial immediately releases the binary data that is used to generate the associated ProceduralTextures as well as the storage for the material's decompressed texture inputs, if any. Furthermore, it also prepares both the source SubstanceArchive and the material's input Texture2Ds for unloading. A "frozen" ProceduralMaterial cannot be rebuilt or cloned, nor can its inputs be set.
For the SubstanceArchive/Texture2D unloading to take place, it is necessary to call Resources.UnloadUnusedAssets after freezing the ProceduralMaterial(s) you want to freeze.
Calling FreezeAndReleaseSourceData does nothing in the Editor, but invalid API calls made after freezing a ProceduralMaterial will be logged to the console.
See Also: Resources.UnloadUnusedAssets, ProceduralMaterial.isFrozen.