Small Colliders Colliding When They're Not Expected To

Hello All,

I have a problem in my project that I'm struggling to understand. I'm sure there is some physics or collision value that I need to adjust to make this work, but I'm not sure what that might be.

When I grab my object in game mode, with the XR grab interaction, and move it "near" my boxes I want to collide, it collides much farther away than I want/expect.

I have 1 object, a scalpel, with a Rigidbody and a small sphere collider. I have the XR Grab interactable using velocity tracking. The big box on the handle of the scalpel is a trigger to grab from the XR interactable. The scalpel is on the "Cutter" layer and the boxes are on the "Cuttable" layer.

Scalpel settings:


Sphere collider on the scalpel:



When I run the scene, I grab the scalpel, place it near these boxes and it collides way farther away than the sphere collider is, as seen here:

Reference image of the boxes before play; these have a script that checks "OnCollisionEnter" and if it does, disables the gameobject:

Here is my collision matrix to show cuttable (boxes) only affected by cutter (scalpel):


Hopefully I added enough detail to present a straightforward question.

My hypothesis are:
1) There is a scale factor for collisions that I need to set lower somewhere
2) The velocity tracking portion of the XR Grab interactable is creating/adjusting some collider I can't see
3) I messed up my layer collision
4) Something is up with my Rigidbody collision detection


Thank you for all the help; have a wonderful day!

 

I was able to figure out what was happening. My hypothesis 1) was correct. I needed to decrease the "Default Contact Offset" in the "Project Settings/Physics" tab.