How do you simulate an LCD projector where a lamp projects a patterned light onto a surface? (cycles)(cycles) I found an answer for Blender Internal engine at I want to make a projector show an image displayed on surfaces

But I want to accomplish something similar in Cycles.  I tried attaching a texture node to the lamp's node tree, but it seems the color pattern is based on the world coordinates and does not rotate with the spot lamp.



What is the correct node setup for a cycles lamp so that its texture rotates and moves with the lamp?
You can do this with a spotlight using the pretty much the same node setup as you have but with an additional mapping node to position the image.



You also need to be sure to set the spotlight light size to something small or your projected image will look blurry. 



And the result. 



Update:

Here's it working with your blend file, no settings changed: