How to increase clearance for OMPL planners in MoveIt?

I’m working on Ubuntu 18.04 with ROS melodic. I’m controlling my robot using MoveIt! and the OMPL library.
I’m having some problems due to the fact that the OMPL planners are planning trajectories that pass extremely close to the obstacles in the planning scene (it looks like they leave zero clearance).
Can anyone help me solve this problem by forcing the planner to increase the clearance? (the minimum allowed distance between trajectories and obstacles)

I’d really appreciate your help.
Thank you very much in advance.

Hello everyone. Just a follow up of what I discovered up to now regarding the problem that I have.

I managed to introduce paddings on my robot model in order to force the planner to keep a certain safety distance. The result is that paddings are successfully set and used every time collision checks are called, but the planner/state sampler is not taking them into account and is still planning without any clearance from the obstacle.

The same problem was highlighted in but I haven’t found any solution yet.

Does anyone know how I could proceed?