Luka, SimpleShadow was built for triangular faces, it currently does not support faces with more than 3 vertices, which is the case usually when using vector elements such as text.
The class needs to be extended to consider more than v0, v1 and v2 in each face. Not sure how quick I could do it, but I'll keep the problem in mind. On the meantime, if you want to take a look at simple shadow yourself, please go ahead!
