Hey guys.

I want to make a mask that starts white and falls off to black from the centre of a tube which is on an angle. Any ideas?

You need to think about what you are asking. To make a mask, means values that change.
How is a solid piece of geometry that only has points around it's diameter going to store these values?

What you are asking is a volumetric effect, density changing from the centre outwards for example.
What type of effect are you trying to do? That might help guide the conversation better.


L