[Bf-funboard] ] constraints

Jean Montambeault bf-funboard@blender.org
Tue, 08 Jul 2003 08:16:52 -0400

Ton Roosendaal wrote:

> Hi,
> Sorry, but I miss the point as well Jean...
> Please elaborate the statements below:
>> split up it's kind of constraints
>> (which are and utterly different animal than what we call 
>> constraints  in Blender for now, I hope that we can agree on that at 
>> least) 

The way parenting 'constraints' its children let us free to transform 
the children at will.
The way our present constraints operates, if you 'Copy location' the 
constrained object can't be moved independantly.
 From the user's point of view the difference is absolute although it 
could not be so from the programmer's point of view.

Something else that probably has no meaning from the programmer's point 
of view but makes a lot of sense from the user's :
when defining a mini-coordinate system, I fine tune my animation and, 
once satisfied, give to every element a parent, usually an empty.
 From the programmers standpoint this is just constraining as usual. 
 From my user's point I have no use for the concept of constraint at all 
; it wouldn't be fertile. What I'd rather see is a bunch of children 
*using* the parent to extract coordinates from it. Other than that the 
parent has no influence and could be in China for what I care.
 If you accept that conceptualisation you get an unexpected extention of 
the tool that can proove very rich.
I understand that this is not what the algorithm says but it has no 
importance. The use extends the tool : always.
I am sure that if we go Matt's way and invent all kinds of constraints, 
even when some may seem to be of limited usefullness at first, you never 
know what side effect might develop, you never know what the creativity 
of the user will extract out of them. The perspective really fills me 
with enthousiasm.

> and:
>> But entirely getting rid of a simple, efficient , universally  
>> understood and used tool won't ever make the smallest bit of sense 
>> to  me. 

Then again this must be seen from the user's point of vue, who, sorry to 
say, doesn't care for the underlying algorithms.
The user's may come from another software and chances are that he is 
familiar with parenting since it is of an almost universal use : why 
make his life difficult when leaving a minimal parenting system to greet 
him would make the transition so much easier : universality and 
efficiency since it facilitates the communication.
( Not to worry : with a powerful constraining system as discussed here 
nobody will want to live without it.)
'Make parent' is also a quite simple way to access to an often used set 
of constraints : simplicity and efficiency.

Give the poor soul that much no matter how it is achieved : use your new 
constraint system at will but make it transparent on that occasion for 
the user.

Hope this is clearer.