Locking the vertex weight when adjusting the normalise values

I might have missed it in an earlier lesson, but when adjusting the nomalise values eg 33:30, and then hitting the normalise button, why does the value I just set then recalculate to something else? I assume this is the intended behaviour, but what would I do if I wanted the value to be specific?

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  • Wayne Dixon replied

    Hi Harris.

    Good question.  And I'm sure when I explain why it does that, you'll be like "oh, of course"

    When you interact with a single vertex's weight using that panel, you are essentially changing ALL the weights. But once you change that number - the numerical feedback is incorrect.  Blender normallises everything under the hood so as soon as you touch it, it is no longer what you see is what you get.

    It would be extremely costly for it to update and keep all the groups updated at the same time - imagine your computer fans whirring every time you tried to adjust a value. Plus it would also need to alter the value that you were currently changing....which would make it difficult to actually let the user change it.  (kind of like a self driving car trying to steer the wrong way while you are trying to park).

    The easiest and possibly the best solution is to let it get out of sync for the sake of usability.


    So what if you want it to be a specific value?

    Another excellent question.
    I'm going to first answer your question with a question (don't you hate that)...but then later I will give you some solutions.

    Do you really need it to be a specific value?

    Sometimes the answer is yes, but that usually means it should be a logical number- like 1.0, 2/3, 1/2 etc
    Depending on how many other groups there are, it's usually really easy to know what those values should be too.

    Another way is to just set it to that value a few times in a row.  Set it, normalise, set it, normalise, set it, normalise.

    It will inch closer to the value that you want until it's close enough.

    Another more cumbersome way would be to lock that vertex group then normalise, then unlock.
    Honestly, I've never bothered to do that because it seems like a lot of steps and if you then forget to unlock, you are going to make an even bigger mess of the weights.


    But if you really do need precision here's what I do.

    - Get it as close as you can with the weight brushes.

    - then tweak the remaining verts individually but choose the most logical group to ADD or SUBTRACT to/from.

    -change that, normalise, and don't worry about what the numeral values are if the model is deforming correctly.


    Hope that helps.






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