NurbsSurface.EvaluateNormalizedPosition2
 
 
 

NurbsSurface.EvaluateNormalizedPosition2 operator

Introduced

v4.0

Description

Returns the Position, U tangent, V Tangent and Normal at a given normalized UV value in the same order as the output arguments in NurbsSurface.EvaluateNormalizedPosition.

Note: This method must be used with scripting languages that don't support arguments passed by reference such as JScript and PerlScript. For more information on getting output arguments, see About Output Argument Arrays.

C# Syntax

Object NurbsSurface.EvaluateNormalizedPosition2( Double in_dUValueNormalized, Double in_dVValueNormalized );

Scripting Syntax

oArray = NurbsSurface.EvaluateNormalizedPosition2( UValueNormalized, VValueNormalized );

Return Value

Array that contains SIVector3 objects representing the position, u tangent, v tangent and normal at the given UV.

Parameters

Parameter Type Description
UValueNormalized Double The normalized UValue(0.0 to 1.0) at which we want to evaluate the surface.
VValueNormalized Double The normalized VValue(0.0 to 1.0) at which we want to evaluate the surface.

Examples

JScript Example

/*
        This example illustrates how to retrieve the normalized UV value from a specific Knot
        and how to use that to evaluate its position. 
*/
var oSphere = ActiveSceneRoot.AddGeometry( "Sphere", "NurbsSurface" );
var oSurfaces = oSphere.ActivePrimitive.Geometry.Surfaces;
var oSurface  = oSurfaces(0);
var aUKnotValues = new VBArray(oSurface.UKnots.Array);
var aVKnotValues = new VBArray(oSurface.VKnots.Array);
var aUVNormalizedValues = new VBArray( oSurface.GetNormalizedUVFromUV2(aUKnotValues.getItem(3),aVKnotValues.getItem(4)));
var aValues = new VBArray(oSurface.EvaluateNormalizedPosition2( aUVNormalizedValues.getItem(0), aUVNormalizedValues.getItem(1)));
var oPosition = aValues.getItem(0);
var oUTangent = aValues.getItem(1);
var oVTangent = aValues.getItem(2);
var oNormal = aValues.getItem(3);
LogMessage( "Position: " + oPosition.x + ", " + oPosition.y + ", " + oPosition.z );
LogMessage( "Tan U: " + oUTangent.x + ", " + oUTangent.y + ", " + oUTangent.z );
LogMessage( "Tan V: " + oVTangent .x + ", " + oVTangent .y + ", " + oVTangent .z );
LogMessage( "Normal: " + oNormal.x + ", " + oNormal.y + ", " + oNormal.z );
//--------------------------------------------------
// Output of above script:
//INFO : "Position: -4.718447854656915e-16, -2.828427124746189, 2.8284271247461916"
//INFO : "Tan U: 1, 0, 1.8784326741201244e-16"
//INFO : "Tan V: -5.3007381947367376e-17, 0.706986783671791, 0.7072267583409271"
//INFO : "Normal: -1.3280270746201882e-16, -0.7072267583409272, 0.7069867836717909"