question about collision and GeomNode

Hi, I’m fairly new in Panda3d and I still don’t know well how it works.

I try to detect collisions with events. I see in the manual that the Into object doesn’t need to be a collider registered in the traverser. But how to do that?
Let say I have an actor with a spherical CollisionNode and another actor which is a simple mesh, also spherical.

If I don’t create a CollisionNode for this second actor, it is simply ignored by the traverser. So, my question is: do I have to create a CollisionNode for every object related to a collision interaction?
If yes, what’s the mean of the collision pattern string %ig?
If no, how to make my simple visible geom collide with my actor?

If you wonder why I don’t want to add a CollisionNode to my second actor, it’s because I may have much more of it and I don’t want to manage a collider for each of them if I can avoid it. It may be a wrong understanding of collisions but since I saw this option of collision between a CollisionNode and a simple mesh, I wanted to test it.

Thank you in advance for your answers.

ok, the bitmask was the trick.
Sorry it took so much time for me to figure this out from the doc.

Hi. You got yours working. I am having a great deal of difficulty working out how do do this. Could you help me please?