but why were their normals different?
i want to understand this.
i have adjusted all vertices - and their normals are fine. yet only these three are different.only the three at the center(which was a single edge that i subdivided) had outline normals.
i understand this thing generally, but what made these three change? because of the subdivide?
can you help me understand or give a good link about this?
I believe you started with a circle. Once you create faces from a circle the direction of the normals could be either in or out. Not sure why, but just remember to always recalculate normals afters extruding a circle.