Get U-position of nurbs curve point? 2004-06-18 - By Felix Gebhardt
Back
Hey Holger, if you use EvaluatePosition with an even number you already have
the knot position. At least if the curve parametrisation is non uniform.
Cheers,
Felix
-- 8< -- ---- ---- ---- ---- ---- ---- ---- ---- ------
NewScene
SICreateCurve "crvlist", 3, 0
SIAddPointOnCurveAtEnd "crvlist", 3, 0, -3, False, 0
SIAddPointOnCurveAtEnd "crvlist", -1, 0, -2, False, 0
SIAddPointOnCurveAtEnd "crvlist", 2, 0, 1, False, 0
SIAddPointOnCurveAtEnd "crvlist", -1, 0, 3, False, 0
SIAddPointOnCurveAtEnd "crvlist", -4, 0, 1, False, 0
SIAddPointOnCurveAtEnd "crvlist", -3, 0, -2, False, 0
SIAddPointOnCurveAtEnd "crvlist", 0, 0, -3, False, 0
SetValue "Views.ViewA.TopCamera.camvis.compobjselknot", True
SelectObj "crvlist", , True
set oCurve = Activesceneroot.findchild("crvlist")
set oCurveGeo = oCurve.Activeprimitive.Geometry
SetObjPos "vPos", oCurveGeo.Curves(0).EvaluatePosition( 1.0 )(0)
'======================================== Function SetObjPos(sChildname,
vInVector)
'========================================
dim oObj, tTrans
if Not typename(vInVector) = "ISIVector3" then
set vInVector = XSIMath.CreateVector3
end if
if typename( Activesceneroot.FindChild ( sChildname ) ) = "Nothing" then
set oObj = Activesceneroot.AddNull (sChildname)
oObj.parameters("size").value = 0.5
MakeLocal oObj&".display", siNodePropagation
SetValue oObj&".display.wirecol", 367
end if
set oObj = ActiveSceneRoot.FindChild ( sChildname )
set tTrans = oObj.Kinematics.Local.Transform
tTrans.SetTranslation vInVector
oObj.Kinematics.Local.Transform = tTrans
'=========== End Function
'===========
-- 8< -- ---- ---- ---- ---- ---- ---- ---- ---- ------
Schoenberger wrote:
> I unerstood his way, But I would use te position of the knot instead of
> the position of the control point to
> get the new position. But I forgot that the Knot doesnot have a position
> array....
>
> damn
>
>
>
> >> -- --Original Message-- --
> >> From: owner-xsi@(protected)
> >> [mailto:owner-xsi@(protected)] On Behalf Of Bradley Gabe
> >> Sent: Friday, June 18, 2004 7:40 PM
> >> To: XSI@(protected)
> >> Subject: Re: Get U-position of nurbs curve point?
> >>
> >>
> >> What Aloys said...
> >>
> >> 1- Get a pointer to the ControlPoint collection.
> >> 2- Get a pointer to the ControlPoint object at its index
> >> in the collection.
> >> 3- You can access X,Y,Z values of the point as they are
> >> properties of a
> >> ControlPoint object.
> >> 4- Put the XYZ values into a vector3() object.
> >> 5- Even though the control point is not directly on the
> >> nurbs curve, you
> >> can use the GetClosestCurvePosition() method with the
> >> vector3() object
> >> as input. It will return a collection of data about the
> >> coordinates you
> >> input.
> >>
> >> If you're doing this in jscript, you'll want to search the
> >> SDK docs for
> >> any jscript examples on these methods. As far as I know,
> >> it's the only
> >> place to get examples of what data is returned at what
> >> index position of
> >> the return collection.
> >>
> >> Good luck.
> >>
> >> -Brad
> >>
> >> > Hello,
> >> > I think you can't!
> >> > The main reason is that control points are not on the
> >> curve, only
> >> > knots are.
> >> > I would advice you to use the GetClosestCurvePosition
> >> method of the
> >> > NurbsCurveList object with the position of th control
> >> point : it will
> >> > return you the u value.
> >> > Good luck!
> >> >
> >> > --
> >> > Aloys Baillet - R&D @ La Maison
> >> > --
> >> >
> >> >
> >> >
> >> > Schoenberger wrote:
> >> >
> >> >> Hi
> >> >>
> >> >> I'm trying to get the position of a nurbs point on a curve.
> >> >> Someting like a length from start of the curve to the point.
> >> >> I have a little script, that does it, but I need
> >> something that works
> >> >> with the object model.
> >> >> What I have:
> >> >> GetCurvePercentageAtKnotIndex "crvlist",
> >> MyPointIndex, perc
> >> >> clength = GetCurveLength("crvlist")
> >> >> PostionOnCurve = clength*perc/100
> >> >>
> >> >> Now I want that result, but with the object model.
> >> >> What I have found till now is:
> >> >> .Geometry.length
> >> >> .Geometry.curves(0).GetPercentageFromU
> >> >> .Geometry.curves(0).ControlPoints
> >> >>
> >> >>
> >> >> Perhaps I am stupid or missed something in the docs,
> >> but how to get the
> >> >> U position of a Control point?
> >> >> With the U position I could get the percentage and
> >> everything would be
> >> >> fine.
> >> >>
> >> >>
> >> >> Holger Sch�nberger technical director
> >> >> The day has 24 hours, if that does not suffice, I will
> >> take the night
> >> >>
> >> >>
> >> >> ---
> >> >> Unsubscribe? Mail Majordomo@(protected) with the
> >> following text in
> >> >> body:
> >> >> unsubscribe xsi
> >> >>
> >> >>
> >> >>
> >> >>
> >> >>
> >> >
> >> > ---
> >> > Unsubscribe? Mail Majordomo@(protected) with the
> >> following text in
> >> > body:
> >> > unsubscribe xsi
> >> >
> >> >
> >>
> >> --
> >> Bradley R. Gabe
> >> Industrial Light & Magic
> >>
> >>
> >>
> >>
> >> ---
> >> Unsubscribe? Mail Majordomo@(protected) with the
> >> following text in body:
> >> unsubscribe xsi
> >>
>
>
> ---
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