Transparency gradient for cylinder

[peterparker]

Turns out I was wrong. Around the ground rotation event there is a fade-out/fade-in sequence, which manipulates the alpha value of the ground model. This fading process actually is the culprit.

Now I only need to find out, how to fade out the ground without manipulating its alpha. And it would be interesting to understand, why the fading breaks my tube transparency, in the first place.

(sorry for the confusion, this code isn't originally by me)