C4D has a capable hair shader. If you are using a third party renderer such as V-Ray or Arnold, they will also come with custom shaders that will handle hair during rendering.
learn how to use the amazing Hair Shader in Arnold for Cinema 4d
Arnold’s Hair Shader is one of the best hair shaders out there, according to Mograph Plus’ Kamel Khezri. The Cinema 4D native Hair Shader will handing tangible attributes for the hair group. This would include things like length, taper, kink, and curl. The Arnold hair shader can be set to control the visual attributes for the hair, such as color, specularity, opacity, and transmission.
The two can work together to create really great results.
This tutorial makes its way to use as a part of the Mograph + Comprehensive introduction to ARNOLD for Cinema 4D course, which takes a look at using the Arnold skin shader and hair shaders in detail. Covering how you can realistically create subsurface scattering and hair shaders for your character work.
The series runs around 8 hours and 20 minutes, and more information can be found on the Comprehensive introduction to ARNOLD for Cinema 4D page.