dummy relative to vertex

[cdwalt]

I have found that if I use the getKnotPoint call then I can get the position of a vertex.

Does anyone know if you can use this to get the Knot point of a vertex in a modifier on top of a stack...i.e. a edit spline modifier on top of a reactor rope modifier?

[ZeBoxx2]

I have tried with spline constraints but that doesn't work out.
Why did that not work out? Is it because of the dynamic spline?

Can someone point me in the right starting direction for figuring this out?

Some pointer code...

-- get the position of the 2nd knot in the first spline of the selected shape
myPoint = getKnotPoint $ 1 2
[67.1686,20.857,0]

-- find its position on the spline by path (could also get by length)
myPointOnSpline = nearestPathParam $ 1 myPoint steps:10
0.5

-- get the 'direction' of the curve at that point. This doesn't get the 'spin' around that direction (which would hav been equivalent to the 'Bank' option in a path constraint).
-- making sure to use pathTangent, as we got the pathParam. Otherwise, lengthTangent.
myTangentDir = pathTangent $ 1 myPointOnSpline
[-0.250724,-0.968059,0]

-- create a new dummy
myDummy = Dummy()
$Dummy:Dummy01 @ [0.000000,0.000000,0.000000]

-- align position with the knot
myDummy.pos = myPoint
[67.1686,20.857,0]

-- and rotation with the direction of the curve
myDummy.dir = myTangentDir
[-0.250724,-0.968059,0]


Now, as per your second post, you mentioned that you're using an edit spline. If you are using this at all to insert/remove new knots, then I'm thinking you don't want to use the knots at all. Just get the pathParam or, better, the lengthParam so that you will always get a consistent position along the spline curve regardless of how many knots are on it.


Most of the above functions are in: "Shape Common Properties, Operators, and Methods". The others (with a lot of equivalent functions) are in the "SplineShape" topic.

[ZeBoxx2]

Does anyone know if you can use this to get the Knot point of a vertex in a modifier on top of a stack...i.e. a edit spline modifier on top of a reactor rope modifier?

Not too sure that you can... I think the spline operations tend to work on the base object, not on the output of the entire modifier stack. You might have to make a copy and convert to that to a SplineShape (or collape the stack), then operate on that instead.

[JHaywood]

Regarding modifiers, I was just dealing with this recently also. As far as I can tell, all the spline operations happen on the base object. So like ZeBoxx2 said, you need to create a copy and collapse that, or collapse the spline you're working on.

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