Epic Games have released a comprehensive Unreal Engine 4 sample accompanied with documentation that demonstrates use of high-quality character shader techniques.
These techniques are similar to those used in Paragon, Epic's MOBA that's been released on the PC and PS4.
The sample, billed as a 'Photorealistic Character sample' is now available for use in any UE4 project, and the aforementioned documentation should help developers with enhanced shading for skin, eyes, hair and other character attributes, by demonstrating how photoreal characters were created in Unreal Engine 4.
"The purpose of sharing this content is to empower anyone to learn from, explore and deconstruct Epic’s professionally created materials and models." says the press release. This could lead to smaller development teams taking advantage of more powerful tools to achieve better graphics, but as you can see in the 40-second video of the sample here, it's startlingly impressive stuff, although still suffers from the uncanny valley effect.