## NurbsCurve.EvaluatePositionFromPercentage

### Description

Returns a 3D vector containing the position, tangent in U direction, normal and bi-normal at a given percentage along the curve.

### C# Syntax

    Object NurbsCurve.EvaluatePositionFromPercentage( Double in_dPercentage );

### Scripting Syntax

    oArray = NurbsCurve.EvaluatePositionFromPercentage( Percentage );

### Return Value

A 1-dimensional Array containing the position, tangent, normal and bi-normal.

### Parameters

Parameter | Type | Description
--- | --- | ---
Percentage | Double | The percentange (with values between 0.0 and 100.0 inclusive) of the length of the curve at which we want to evaluate the curve.

### Examples

#### 1. VBScript Example

    set oRoot = Application.ActiveProject.ActiveScene.Root

    set oArc = oRoot.AddGeometry( "Arc", "NurbsCurve" )

    aValues = oArc.ActivePrimitive.Geometry.Curves(0).EvaluatePositionFromPercentage( 70.0 )

    set oPosition = aValues(0)

    logmessage "The position at 70%% of the curve is x :" &  oPosition.x	& " y: " & oPosition.y & " z: " & oPosition.z

    set oUTangent = aValues(1)

    logmessage "The tangent in U at 70%% of the curve is x :" & oUTangent.x & " y: " & oUTangent.y & " z: " & oUTangent.z

    set oNormal = aValues(2)

    logmessage "The normal at 70%% of the curve is x :" & oNormal.x & " y: " & oNormal.y & " z: " & oNormal.z

    set oBiNormal = aValues(3)

    logmessage "The bi-normal at 70%% of the curve is x :" & oBiNormal.x & " y: " & oBiNormal.y & " z: " & oBiNormal.z

#### 2. JScript Example

    SICreateCurve("crvlist", 3, 0);

    SIAddPointOnCurveAtEnd("crvlist", -3.951, 0.000, 1.651, false);

    SIAddPointOnCurveAtEnd("crvlist", -3.214, 0.000, -1.884, false);

    SIAddPointOnCurveAtEnd("crvlist", -0.592, 0.000, 1.146, false);

    SIAddPointOnCurveAtEnd("crvlist", 1.660, 0.000, 2.856, false);

    SIAddPointOnCurveAtEnd("crvlist", 3.272, 0.000, -1.224, false);

    GetNurbsCurveListInfo( GetValue("crvlist") );

    function GetNurbsCurveListInfo( oCurveList )

    {

    	var oPosition, oUTangent, oNormal, oBiNormal;

    	var p = XSIMath.CreateVector3();

    	oGeometry = oCurveList.ActivePrimitive.Geometry;

    	// Display curve list info

    	LogMessage( "    Name: " + oCurveList.Name );

    	LogMessage( "FullName: " + oCurveList.FullName );

    	LogMessage( "    Type: " + oCurveList.Type );

    	// Display geometry info:

    	LogMessage( "      Length: " + oGeometry.Length );

    	LogMessage( "      Closed: " + oGeometry.Closed );

    	LogMessage( "   Nb Points: " + oGeometry.Points.Count );

    	LogMessage( "  Nb Control: " + oGeometry.ControlPoints.Count );

    	LogMessage( "   Nb Curves: " + oGeometry.Curves.Count );

    	LogMessage( "   Nb Facets: " + oGeometry.Facets.Count );

    	LogMessage( " Nb Segments: " + oGeometry.Segments.Count );

    	LogMessage( " Nb Clusters: " + oGeometry.Clusters.Count );

    	LogMessage( "Nb Triangles: " + oGeometry.Triangles.Count ); //crashes Softimage

    	// Get the lower-level stuff

    	for ( i = 0; i < oGeometry.Curves.Count; i++ )

    	{

    		LogMessage( "--- Curve["+i+"] ---" );

    		oCurve = oGeometry.Curves(i);

    		// Find the midpont along the curve

    		var aValues = new VBArray(oCurve.EvaluatePositionFromPercentage( 50.0 ));

    		var oPosition = aValues.getItem(0);

    		var oUTangent = aValues.getItem(1);

    		var oNormal = aValues.getItem(2);

    		var oBiNormal = aValues.getItem(3);

    		LogMessage( " Position[x,y,z]: " + oPosition.x +","+ oPosition.y +","+ oPosition.z );

    		LogMessage( "U Tangent[x,y,z]: " + oUTangent.x +","+ oUTangent.y +","+ oUTangent.z );

    		LogMessage( "   Normal[x,y,z]: " + oNormal.x   +","+ oNormal.y +","+ oNormal.z   );

    		LogMessage( "Bi Normal[x,y,z]: " + oBiNormal.x +","+ oBiNormal.y +","+ oBiNormal.z );

    		// Display the info

    		LogMessage( "   Nb Knots: " + oCurve.Knots.Count );

    		LogMessage( "   Degree: "   + oCurve.Degree      );

    	}

    	return(0);

    }

### See Also

NurbsCurve.GetPercentageFromU NurbsCurve.GetUFromPercentage