Relation Constraint FCurve (%)

[dnorthcutt]

Hey Guys,

I'm writing some tools right now to drive bone rotation via a Relation Constraint. I've got everything mostly worked out with creating and connecting nodes in the constraint - but I'm having a bit of trouble with the FCurve (%) node. Does anyone know how to add/modify keys on one of these via script? Any help or ideas would be appreciated. Thanks!

[cmot]

As far as I know, the boxes in a Relation constraint are not animatable. This makes sense considering a Relation constraint is kind of like an expression you create through nodes instead of writing lines of code.

You can set the value of the input of the box if you want through something like this.

def FindAnimationNode( pParent, pName ):#standard find animation node def
    lResult = None
    for lNode in pParent.Nodes:
        if lNode.Name == pName:
            lResult = lNode
            break
    return lResult

constr = None
box = None

for thisConstr in FBSystem().Scene.Constraints:
    if "Relation" == thisConstr.Name:
        constr = thisConstr

if constr:
    for thisBox in constr.Boxes:
        if "FCurve Number (%)" == thisBox.Name:
            box = thisBox
            print box.Animatable #this shows up as False

if box:
    nodeToSet = FindAnimationNode(box.AnimationNodeInGet(),"Position %")
    nodeToSet.WriteData()

In scene with a relation constraint named "Relation" with a box in the relation constraint named "FCurve Number (%)"

I usually make a def like FindConstraint(constrName) and FindBox(constraint,boxName) when working with stuff like this.

[dnorthcutt]

Hey, thanks for the reply. I've got all the box building and connecting working -- I guess I was just hoping to automate the process of setting the keys within an FCurve box. Sounds like maybe it's not accessible via Python?

[middlek]

Do you mean this ?

[middlek]

Re-reading your post I think this is what you are looking for:

from pyfbsdk import *

def FindAnimationNode( pParent, pName ):
                lResult = None
                for lNode in pParent.Nodes:
                                if lNode.Name == pName:
                                                lResult = lNode
                                                break
                return lResult

lRelation = FBConstraintRelation('TEST')

lFcurveBox = lRelation.CreateFunctionBox( 'Other', 'FCurve Number (%)' )
lValue = FindAnimationNode( lFcurveBox.AnimationNodeOutGet(), 'Value' )
lCurve = lValue.FCurve
lCurve.EditBegin()
lTime = FBTime( 0, 0, 0, 20 )
lKey = lCurve.KeyAdd( lTime, 20 )
lKeyFrame = lCurve.Keys
lKeyFrame.RightDerivtive = 7
lKeyFrame.LeftDerivative = 7
lCurve.EditEnd()

~Kristine

[dnorthcutt]

That's exactly what I was looking for - thanks a ton!