Bump maps won't show in profile as will displacement, nor cast shadows. Best used for fine surface details like pores, fine hairs, etc. Not sure that using bump maps will get you the effect you're looking for. In most cases you can get away with using bump without the math subtract node (as you would with displacement), if however bump generated detail intersects (say on lips or some such surfaces in close proximity) it can cause black render artifacts.

Normal maps? Never use them... but yeah, gradient bump channel as mentioned earlier.

K, movie time while my poor computer chugs through a render.

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W10 Pro, HP Envy X360 Laptop, Intel Core i7-10510U, NVIDIA GeForce MX250, Intel UHD, 16 GB DDR4-2400 SDRAM, 1 TB PCIe NVMe M.2 SSD

Mudbox 2022, Adobe PS CC, Poser Pro 11.3, Blender 2.9, Wings3D 2.2.5

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