Shadows on lambert material don't blend

Why do the shadows on a Lambert material not blend?
It looks fine with Phong, but switching to Lambert causes the shadows to look weird.
Here is a screenshot of two point lights:


it’s already set to -0.004
It doesn’t fix the issue.

because Lambert material is “special”. It does the most of its light processing “per vertex”, not “per pixel”. as a result, it has many issues, and you just ran into one of them - congrats :tada: