Is it better to use a cap when using the hair tool to avoid the hair particles from entering the mesh?

Question

I notice on some models there appears to be a cap for lack of a better term on which the hair particles are attached, does this help prevent the inclusion of the particles into the mesh? I'm trying to create a lion main for a pre-made mesh.

Answer 1

Hair caps are usually used because they make controlling distribution of hair strands easier. In my experience vertex groups alone are not always ideal due to how hair children interpolate. A good example is around the things like ears or anything similar should should have a gap in hair emission, where you may have faces with some vertices set to generate hairs, and some space in-between that should not, with vertex groups alone, these partially weighted faces may still get interpolated hairs, but with a cap you can just delete them.

Hair caps may also have slightly different topology that the underlying mesh to control the emission of hairs (e.g. extra loops / edges along where you want a part to be can make the result better defined).

Due to limitations in the collision system for hair they can improve collision handling with some extra setup, see here: How do I stop hair particles going through the body and the head?