Fix crash when moving origin point of child bone in Skeleton Deformation Layer using Bone Tool

[rodolforg]

when moving a child bone with Bones tool

[rodolforg]

As I said here, I still don't know what this code is for.
The commit 9664b8c that inserted this code is from PR #1698, that fix issue #1658, but the commit description and code comment are not related to the PR or to this issue the PR deals.

[rodolforg]

(the forced push was to fix the exception class: from String to Error).

[morevnaproject]

As I said here, I still don't know what this code is for.

Hi! This code is fixing this issue - #1627
Without this code we will have wrong behavior, which is demonstrated in this video - https://www.youtube.com/watch?v=dzTPdNbqS3U&feature=youtu.be ^__^

[rodolforg]

Hi! This code is fixing this issue - #1627

Thank you for pointing the correct issue! :D How can I create the second bone? I can only create child bones :(
Actually, I don't know how deformation layer works (what are those bone pairs?)

[ice0]

@rodolforg, are there any more changes planned? Temporarily switched this PR to "Draft"

[rodolforg]

@ice0 no because I don't understand further than I did lol

[morevnaproject]

How can I create the second bone? I can only create child bones :(
Actually, I don't know how deformation layer works (what are those bone pairs?)

Hi! Here I have recorded an explanation video on how Skeleton Deformation works - https://youtu.be/T1SgaJg44ns
(I hope my explanation is okay ^__^")

[rodolforg]

(I hope my explanation is okay ^__^")

It was great! It's a totally different approach of "regular" skeleton that I didn't realize what was the pair stuff :) Thank you and sorry for my ignorance here

[morevnaproject]

Thank you for help! Please ask again if you need any more clarifications - I'll try to be here as possible. ^__^

[rodolforg]

@morevnaproject by the way, congrats for your NGO accomplishment (I just saw your presentation! ;) )!

[morevnaproject]

Thank you! It took some efforts and time. Tomorrow will go to receive all official documents on hands. Let's keep rockin'! 🎉

[rodolforg]

If something is left to do in this code slice (but not related to the bug fix) is line 206:

ValueNode_Composite::Handle comp = ValueNode_Composite::Handle::cast_dynamic(value_desc.get_parent_desc().get_parent_desc().get_value_node());

That isn't the way to check if it a Skeleton Deformation bone list parameter :/