Why Lock Normals?

[Anonymous]

So - complete ignorance - why do we need to lock normals? 

Often have to unlock them - never relock them...the world does not end, but I imagine there is some purpose behind it.

And is there a way to see in the viewport whether they are locked or not?

Thanks!

Dave

[osidedan · Accepted solution]

Honestly, you don't need to lock normals unless you have a reason to. I've only ever needed to lock normals on an object when I needed to set custom normal orientation, and didn't want geo edits to mess up the normal direction I set. The only time I've needed custom normal orientation, was to get a certain effect from a vertex shader in a game engine.

To see if they are locked or not in the viewport, you can select your object, then go to display>polygons>vertex normals. If they are locked, they will be yellow. If they are unlocked, they will be green (these only show if the object is selected):

If you want to see the difference between locked/unlocked, you can grab a vertex, edge, or face on your object and move it around. In unlocked mode (green), the normals around the selection update to blend with the change. In locked mode, they do not. Hope that helps!

[olarn]

Because unlocked normals are auto-calculated.

Want custom normal line unrelated to neighboring vtx position? lock required.

BTW if normals were modified by component editor/ modify normal tool etc, maya will already be locking it for you.