#set ambient value to 0, color to black, detach alternate diffuse 
import poser 
mats = poser.Scene().CurrentFigure().Materials()
for mat in mats:
	nod = mat.ShaderTree().NodeByInternalName("PoserSurface")
	inp = nod.InputByInternalName("Ambient_Value")
	inp.SetFloat(0)
	inp2 = nod.InputByInternalName("Ambient_Color")
	inp2.SetColor(0,0,0)
	inp3 = nod.InputByInternalName("AlternateDiffuse")
	inp3.Disconnect()
	mat.ShaderTree().UpdatePreview()
poser.Scene().DrawAll()