How to have Geometry Collection Ignore a Collision

Hi Guys,

I’ve got a catapult that shoots a projectile at a wall. When the projectile hits, it generates a physics field that does damage to my Geometry Collection.

However the actual projectile is also doing some damage because it needs to have physics enabled to pass through the air like a rock. This is a problem.

How can I have the geometry collection (my wall) ignore the stress caused by the impact of the projectile?