Options for the compressed texture formats that are available on the target build platform.
| Unknown | Use an undefined texture compression format. | 
| ETC | Use ETC1 texture compression (or ETC2 for textures with alpha). | 
| ETC2 | Use ETC2 texture compression. | 
| ASTC | Use ASTC texture compression. | 
| PVRTC | Use PowerVR texture compression. | 
| DXTC | Use S3 texture compression. | 
| BPTC | Use BPTC texture compression. | 
| DXTC_RGTC | Use DXT + RGTC(BC4, BC5) texture compression. |