1. Just load opacity map into Opacity window. The loaded image must be divided into 2 parts black and white. White make it visible black invisible. Then change opacity to control them You can test it by loading into Opacity image window any image from assets that have white and black (or any other color) and play with Opacity. In image you need to play with offset X, Y for placing opacity map into desired and correct position
2. If you know Ps you can load your object into Ps and use there Cross Section. Then export it as Obj and import into Dn back.
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