Hi guys ,
i am beginner with jme and i am working on one project now … the first think i am working on is to make a spot light looking like a projector that the spot will look like a rectangle not like a circle … so my idea was to create 4 boxes that will cover the light (close to the spot light) so that you will see a rectangle … I created one box that will receive the light … some spot light … and two boxes … the first one shows where the spot light position is … the second (rectangle) is that should cover or block the light … a set some PssmShadowRenderer … and the result was bad … actually on the left picture you can see what is the result on the right one … what i need … can you please give me some tips if it is possible to make it like on the right picture ? thanks … ( and sorry for my english) 
Best advice is probably to learn a bit more about the engine and opengl rendering at first. This is a serious attempt to help. For example shadow, light and occlusion are totally separate things that need separate handling and need to be instructed to talk to each other for specific situations (games are a lot of smoke and mirrors). This is why any attempt to help you at this stage might result in a working example like you want but you’ll most probably run into new problems quickly if you don’t 100% understand why the solution works like it does.
So, I suggest you at least work through the HelloMaterial and HelloPicking tutorials and then look at the wiki pages about light and shadow, as for example this one.
What normen say, and what you’re trying to achieve is usually done with projected texture.