Fix vessel deformation bug

[faberno]

• fixed vessel deformation bug
• catched cosine_scaling_factor = 0 case

Please check the following before creating the pull request (PR):

• [x] Did you run automatic tests?
• [x] Did you run manual tests?
• [x] Is the code provided in the PR still backwards compatible to previous SIMPA versions?

Provide issue / feature request fixed by this PR

Fixes #392