Add this script to a "Batch Script" editor (F10) and execute it with Script > Run.
The script activates the "WetDry Map" feature and the appropriate export resource for objects inside a group named "Objects":
textureResolution = 1024
filterLoops = 1
filterStrength = 0.1
pixelStrength = 255
ageing = 0.5
objectGroup = scene.getGroup("Objects")
groupNodes = objectGroup.getNodes()
for entry in groupNodes:
if (entry.getType() == TYPE_OBJECT):
entry.setParameter("WetDry texture", True)
entry.setParameter("Resolution", textureResolution)
entry.setParameter("Filter loops #", filterLoops)
entry.setParameter("Filter strength", filterStrength)
entry.setParameter("Pixel strength", pixelStrength)
entry.setParameter("Ageing", ageing)
entry.activeExportResource(4, True) #activate the wet-dry option with code 4
entry.activeExportData(True) #activate the object's global export resource