Determine clearance between objects? Minimum distance

I am preparing my objects for 3D Printing, including interlocking parts. I didn’t find a suitable tool or method to validate that my objects do not get closer to each other than, say 0.5 units.
Does anyone have a good idea or trick to measure clearance or visualising where minimum distance may be breached?

There might be a better way but looks like ruler/protractor thickness measurement follows surface normals, so if you turn the normals pointing inside it’s then possible to measure the gaps between objects or mesh parts.

Would be better if 3d print tools and mesh analysis had a offset value for intersection and would allow negative value but that is not available.

Thanks! I didn’t know this function and it is really quite helpful. But yeah, a proper analysis tool would be even better.
If anyone still has an idea, such as temporarily extruding along normals - or adding a coating with a specific thickness on the outside of the object?