Reason: I have a texture for lip makeup which can't be plugged into MBLab_Skin (not without changing the skin texture and losing displacement information), so I used to use it plugged to a "Shader to RGB" which was plugged alongside the makeup texture to a "Multiply MixRGB" (whose Fac comes from the makeup's alpha channel) which was plugged to a Diffuse BSDF feeding the Material Output. Then I needed to switch to Cycles rendering engine (I was using Eevee), and for some reason the MBLab_Skin doesn't work when plugged to the "Shader to RGB", but using "Mix Shader" alone wouldn't give the result I expect. I threw some approaches to it until I came up with the idea "what if I use a Emitter with a negative value so it becomes a 'Absorber'?" and, to my surprise, it accepts negative values and it works to absorb light... except it literally results in a "negative", so I further added an "Invert Color" to the pipeline, and voila.
I'm using this for a lip makeup. Physically speaking, pigments (and cosmetics) work by absorbing light which would be reflected from the underlying medium (such as the lips' skin), so it's the closest to a real-life makeup.
By the way, for some reason Cycles + Denoise results in a quite better result, at least in the viewport, but then it struggles to render properly with lower samples because Cycles is all about additive noise.
#blender #makeshift #gambiarra #3d #modelling #3dmodeling #3dmodelling #blendercycles #3dart







