pipe light shines trough??

I make a pipe by extruding a nurbs circle along a bezier line. Then I add a material to the pipe and now I want to move the camera through the pipe. I got this all working, but one thing irritates me: Inside the pipe it should be dark, shouldn´t it? But in fact, I get the same colors and light as outside!? How can I make the wall of the pipe opaque?
thanks for any help!

Turn on raytracing for the light, and raytracing in the render buttons. That should work.

There’s 2 things you can do. 1, turn your pipe into a Mesh with Alt-C and ExtrudeRegion, then shrink the extruded part inwards with Alt-S. Now use a Spotlight with Buffshadows with HaloStep about 5 and Bias 100 to 150. (that’s not a very elegant solution)
2) Isolate the pipe on a seperate layer and light it with an Area light on the same layer (set to Layer in the lamp buttons). Then parent another Area light to your camera pointing straight ahead and set to Negative in the lamp buttons and Layer on the same layer as the pipe. Set the Energy a little higher than the light outside.


Well, thanks a lot for your answers, I will experiment with your suggestions!