[Bf-funboard] Transformations, deltas and offsets

[Jeffrey]

A while ago, there was a thread 
<http://lists.blender.org/pipermail/bf-funboard/2015-April/006106.html> 
in bf-committers about parenting offsets and whatnot. I was thinking 
about this tonight and it got me wondering: if we exposed the offset to 
the user, could we rethink how applying transforms works? When you apply 
location, for example, blender moves the origin of the object to the 
world origin and just moves the mesh data where you expect it. However, 
when you try to rotate or scale the object from there, it defaults to 
moving from the origin, which then makes it difficult to further 
transform without the cursor or resetting the origin.

My issue with this is that it moves the origin back to world origin. 
Honestly, this bugs the hell out of me. If I want to move the origin, 
I'll do that manually.

I am proposing we expose the offset to the user in a way that is 
separate from the object's transforms. Perhaps it can be in a 
collapsible panel directly under the transforms and labeled "Offset from 
Parent" to differentiate, or perhaps under "Relations" with the parent 
selector. The way I see this functioning is always relative to its 
parent object (or in the case of no parent, the world/scene), hence 
putting it under "Relations."

This differs from delta transforms because delta transforms are relative 
to the object's current position, not to its parent. While they can both 
be used to the same ends, the purposes and underlying math are 
fundamentally different. The values would be non-keyable and lockable. 
I'm not entirely sure how rotation offset would work, since this is 
based on the parent, not local space. Delta rotations already follow the 
mode of normal transforms (ie quats or eulers), so perhaps it could 
function similarly.

I hope to start a discussion with this. What are your thoughts? If this 
is technically unfeasible or impratical, why? If you think it should be 
implemented, do you have any suggestions to make it better? I've started 
a thread <http://www.blenderartists.org/forum/showthread.php?376657> on 
BA where discussion can take place, too.

-- 
Jeffrey "Italic_" Hoover