Wood Carving/Whittling VR Mechanic

I’m creating a VR game and want to make a way to use a knife to carve out sword handles from wood. I saw it was done in Unity by detecting which polygons were touching the knife at any point, but as a beginner I have no idea where to even start with replicating this. Any advice on how to best set up the whittling mechanic would be very helpful. Thanks yall!

Create a VR whittling mechanic by using collision between the knife and wood material. Use raycasting to identify intersecting areas and alter the shape of the wood material accordingly. Additionally, add audio and visual feedback to create an engaging experience for players.