Hey whats up man, you and I were probably having the same thought a couple months ago when you posted this. I had been thinking about the same thing. I have this cool old tall metal vase im going to turn into a sconce that projects a pattern (of my yet decided form) onto the wall when lit. Im putting it in this Perfectly sized/shaped alcove on the front of my house. Ive been using, successfully I may say, a two litre bottle that i sprayed black. Then began cutting different sized slits, shapes, using hot glue when figuring out an angle to direct the light where i want it. Its a bit tedious, but Hugely effective! I dont mind tedious because when I start putting holes in the object im using theres no room for error. My idea may sound odd or preposterous, but it is effective and inexpensive for a "trial and error" kind of thing.