How to use the BlenderPhotoscannedMaterialCollection :
1. Set Blenders Feature Set to Experimental.
2. Add the subdivision surface modifier to the object which should use the materials and enable Adaptive.
3. Click on file, append and then select Materials.blend
4. Select Materials and choose the ones you want.
5. Then just select the material for the object.
6. You can adjust the displacement strength by changing the value of the math node.
7. To refresh the viewport double click tab on your keyboard.