Hey Wizards!

I'm just trying to better understand SDFs and i've come across an interesting behaviour but unsure why it is the way it is.

So I've got a nice amount of spaghetti SDF and subtracting that from the sphere. my question is how does subtracting SDF from SDF result in detail such as this? The imprint on the sphere is consistently at a certain depth and if i unsqish my spaghetti and have the SDF lines wrap around the sphere, i get lines on the surface of the sphere again no deeper than the same test where i can the SDF lines going through the middle of the object.
I would have kind of expected it to have a similar result if i were to do this as a VDB where it would just carve straight through the object instead

Your sphere SDF has a bandwidth of voxels that are actually active - that is determined by the Exterior / Interior Band Voxels on VDB from Polygons. Up the Interior Band, or turn on “Fill Interior” and you will get the result you expected.