The type of generated image in a ProceduralMaterial.
| Unknown | Undefined type. | 
| Diffuse | Diffuse map. | 
| Normal | Normal (Bump) map. | 
| Height | Height map. | 
| Emissive | Emissive map. | 
| Specular | Specular map. | 
| Opacity | Opacity (Tranparency) map. | 
| Smoothness | Smoothness map (formerly referred to as Glossiness). | 
| AmbientOcclusion | Ambient occlusion map. | 
| DetailMask | Detail mask map. | 
| Metallic | Metalness map. | 
| Roughness | Roughness map. |