DCP DustMap

DCM - Data Channel Modifier

Produces a map for dust that settles on top of whatever faces that are top facing (world).

Extract preset to:

C:\Users\xxx\AppData\Local\Autodesk\3dsMax\2017 - 64bit\ENU\en-US\plugcfg\DataChannelPresets

Then in your DCM, load it as a Preset.

Of course, if you want your Dust 'fixed', simply change the Vector to Local instead of World...or if dust

is coming from a direction (rickety door in an old ghost town) then use Node Look At

(Snow, bird droppings...anything goes...)

(Thought maybe I should rename it to DCP instead, = DataChannelPreset)