This post is a summary of the tips given by Epic Games technical-artist Min Oh in his GDC 2017 lecture about improving photo-realism in product visualization, more specifically, how to render high quality surfaces.
I recommend watching the full lecture:
Render sharper reflections by increasing the Cubemap resolution of reflection captures: Project Settings > Engine > Rendering > Reflection > Reflection Capture Resolution
* use powers of 2 values i.e. 256, 512, 1024….
Improve the accuracy of environment lighting by increasing the Cubemap resolution of the Skylight:
* use powers of 2 values i.e. 256, 512, 1024….
Improve screen space effects accuracy like screen space reflections by setting the engine to compute high precision normals for the GBuffer:
Set Project Settings > Engine > Rendering > Optimizations > GBuffer Format to: High Precision Normals
Use a high degree of tessellation (subdivision) for the models pre-import.
Simpy put: Use high quality models.
Improve the surfaces tangent space accuracy, and as a result also the shading/reflection accuracy by setting the model’s static mesh components to encode high precision tangent basis: Static Mesh Editor > Details > LOD 0 > Build Settings > Use High Precision Tangent basis
Creating materials with rich dual specular layers by enabling material clear coat separate normal input: Project Settings > Engine > Rendering > Materials > Clear Coat Enable Second Normal Set the material Shading Model to Clear Coat and use a ClearCoatBottomNormal input node to add a normal map for the underlying layer: