PolygonMesh.GetApproximatedMeshAndAttributes

Introduced

v5.0

Description

Gives the geometry description of the subdivided mesh given the subdivision rule, the level of subdivision and the discontinuity angle if used. The geometry data is returned in a one dimension array and contains the following values:

1) vertices: polygon vertex 2D array (Nx3) of x,y,z values.

2) polygon data: ordered array of polygon definitions, each polygon is defined by a list of elements, the first element of a polygon definition must be set with the number of indices for that polygon. The ordering of vertices must respect a ccw ordering to get out going normals (right-hand rule). For exampl, an array of polygons with 4 indices each : {4,0,1,4,3,4,1,2,5,4... }

3) polygon node normal array: 2D array containing the normal x,y,z values for every polygon node.

4) polygon node for each polygon face: 1D array containing the number of polygon nodes on each polygon face followed by the corresponding polygon node index.

5) UVW array: 1D array containing the successive UV cluster property ClusterProperty objects, each followed by the corresponding 1D array of UVW values for each polygon node for that UVW cluster property.

6) color array: 1D array containing the successive vertex color cluster prop ClusterProperty objects, each followed by the corresponding 1D array of RGBA values for each polygon node for that vertex color property.

7) material array: 1D array containing the successive polygon cluster Material objects, each followed by the corresponding 1D array of interpolated polygon values of each polygon cluster.

8) weight array: not supported yet.

9) envelope weight array: not supported yet.

Note: The C++ API equivalent function, PolygonMesh::GetGeometryAccessor, returns the CGeometryAccessor object which allows you to get only the data you need, and is therefore a much more efficient way to access this data.

C# Syntax

Object PolygonMesh.GetApproximatedMeshAndAttributes( siSubdivisionRuleType in_SubRule, Int32 in_lSubdivisionLevel, Boolean in_bDiscontinuity, Double in_dDiscontinuityAngle );

Scripting Syntax

oArray = PolygonMesh.GetApproximatedMeshAndAttributes( SubdivisionRule, SubdivisionLevel, UseDiscontinuity, DiscontinuityAngle );

Return Value

1-dimensional Array

Parameters

Parameter Type Description
SubdivisionRule siSubdivisionRuleType This parameter contains the subdivision rule to use for the approximation.
SubdivisionLevel Long This parameter contains the subdivision rule to use for the approximation.
UseDiscontinuity Boolean Specified if we want to use the discontinuity angle or not.
DiscontinuityAngle Double Specifies the angle of discontinuity.

Examples

VBScript Example

'

' This example illustrates how to create a nem PolygonMesh from an ApproximatedMesh

' and how to carry over the attributes.

'

set oCube = ActiveSceneRoot.AddGeometry("Cube","MeshSurface")

set oMaterial = oCube.AddMaterial("Blinn")

'Add Polygon Material and texture

set oPolygonCluster = oCube.ActivePrimitive.Geometry.AddCluster(siPolygonCluster, ,Array(4))

set oMaterial	 = oPolygonCluster.AddMaterial("Phong")

set oImage = AddImageSource( "$SI_HOME\Data\XSI_SAMPLES\Pictures\jio.jpg" )

set oImageClip = AddImageClip( oImage )

set oPhong = oMaterial.Shaders("Phong")

set oColor8Mix1 = oPhong.ambient.connectfromprogid("Softimage.sib_color_8mix.1")

set oColor8Mix2 = oPhong.diffuse.connectfromprogid("Softimage.sib_color_8mix.1")

set oTex2D = oColor8Mix1.color1.connectfromprogid("Softimage.txt2d-image-explicit.1")

call oColor8Mix2.color1.connect(oTex2D)

set oTex2D.tex.source = oImageClip

'Add Polygon Material

set oPolygonCluster = oCube.ActivePrimitive.Geometry.AddCluster(siPolygonCluster,,Array(0,1))

set oMaterial = oPolygonCluster.AddMaterial("Lambert")

'Add UV and VertexColor Properties

set oSamplePointCluster = oCube.ActivePrimitive.Geometry.AddCluster(siSampledPointCluster)

set oUVProp = oSamplePointCluster.AddProperty("Texture Projection")

set oRGBAProp = oSamplePointCluster.AddProperty("Vertex Color")

set oGApprox = oCube.Properties.Find("geomapprox")

oGApprox.Parameters("gapproxmosl").value = 1

MakeLocal oGApprox

ApproxVersion( oCube)

'This function will duplicate the approximated version of the

if selection.count > 0 then

	ApproxVersion( selection(0))

else

	Application.LogMessage "You must select a PolygonMesh"

end if		

'This function will duplicate the approximated version of the

Sub ApproxVersion(in_obj)

	Dim l_NewMesh

	Dim l_Parent

	Dim l_AllInputUVTxtAndCAV

	Dim l_AllOutputUVTxtAndCAV

	Dim l_GeometryApproximation

	Dim l_NewLocalGeometryApproximation

	Dim l_aVertices

	Dim l_aPolygonData

	Dim l_aPolygonNodeNormalArray

	Dim l_aUVArray

	Dim l_aColorArray

	Dim l_aMaterialArray

	Dim l_LocalProperties

	Dim l_attribs

	set l_AllInputUVTxtAndCAV = CreateObject( "XSI.Collection")

	set l_AllOutputUVTxtAndCAV = CreateObject( "XSI.Collection")

	'Check that in_obj is an object

	if not(IsObject(in_obj)) then

		Application.LogMessage "The inputed parameter must be a 3D Object."

		Exit Sub

	end if

	if not(in_obj.BelongsTo("3D Object")) then

		Application.LogMessage "The inputed object must be a 3D Object."

		Exit Sub

	end if

	'If the object is not a PolygonMesh than exit the function

	if in_obj.activeprimitive.geometry.type <> "PolygonMesh" then

		Application.LogMessage in_obj & " has to be a polymesh object"

		Exit Sub

	end if

	set l_GeometryApproximation = in_Obj.Properties.Find("geomapprox")

	l_attribs = in_obj.ActivePrimitive.Geometry.GetApproximatedMeshAndAttributes( _

		l_GeometryApproximation.Parameters("gapproxmosr").value,_

		l_GeometryApproximation.Parameters("gapproxmosl").value,_

		l_GeometryApproximation.Parameters("gapproxmoad").value,_

		l_GeometryApproximation.Parameters("gapproxmoan").value )

	l_aVertices = l_attribs(0)

	l_aPolygonData = l_attribs(1)

	l_aPolygonNodeNormalArray = l_attribs(2)

	l_aPolygonNodePolygonFaceIndexArray = l_attribs(3)

	l_aPolygonFaceParentPolygonFaceIndexArray = l_attribs(4)

	l_aUVArray = l_attribs(5)

	l_aColorArray = l_attribs(6)

	l_aMaterialArray = l_attribs(7)

	set l_Parent  = 	in_obj.Parent

	set l_NewMesh =	l_Parent.AddPolygonMesh(l_aVertices,l_aPolygonData)	

	'Copy local properties

	set l_LocalProperties = in_obj.LocalProperties

	for each iLocProp in l_LocalProperties

			CopyPaste iLocProp,,l_NewMesh,2

	next

	'If the geometry approximation is a local property we set the subdivision level to

	'0 as it is the most likely thing users want to do.

	set l_NewLocalGeometryApproximation = l_NewMesh.LocalProperties.Find("geomapprox")

	if IsObject(l_NewLocalGeometryApproximation) and TypeName(l_NewLocalGeometryApproximation) <> "Nothing" then

		l_NewLocalGeometryApproximation.Parameters("gapproxmosl").value = 0

	end if

	'Add a sample cluster if there's some VertexColors or UVProp

	if IsArray(l_aUVArray) then

		i = 0

		do while i < ubound(l_aUVArray)

			set l_Cluster = l_NewMesh.ActivePrimitive.Geometry.AddCluster(siSampledPointCluster)

			set l_UVProp = l_Cluster.AddProperty("Texture Projection", ,l_aUVArray(i).Name & "_" & l_Cluster.Name)

			ReDim l_UVPropArray(2,(l_Cluster.Elements.Count - 1))

			for j = 0 to l_Cluster.Elements.Count-1

				l_UVPropArray(0,j) = l_aUVArray(i+1)(j*3)

				l_UVPropArray(1,j) = l_aUVArray(i+1)(j*3 + 1)

				l_UVPropArray(2,j) = l_aUVArray(i+1)(j*3 + 2)

			next

			l_UVProp.Elements.Array  = l_UVPropArray

			l_AllInputUVTxtAndCAV.Add l_aUVArray(i)

			l_AllOutputUVTxtAndCAV.Add l_UVProp

			i = i+2

		Loop

	end if

	if IsArray(l_aColorArray) then

		i = 0

		do while i < ubound(l_aColorArray)

			set l_Cluster = l_NewMesh.ActivePrimitive.Geometry.AddCluster(siSampledPointCluster)

			set l_ColorProp = l_Cluster.AddProperty("Vertex Color", ,l_aColorArray(i).Name & "_" & l_Cluster.Name)

			ReDim l_ColorPropArray(3,l_Cluster.Elements.Count - 1)

			for j = 0 to l_Cluster.Elements.Count-1

				l_ColorPropArray(0,j) = l_aColorArray(i+1)(j*4)

				l_ColorPropArray(1,j) = l_aColorArray(i+1)(j*4 + 1)

				l_ColorPropArray(2,j) = l_aColorArray(i+1)(j*4 + 2)

				l_ColorPropArray(3,j) = l_aColorArray(i+1)(j*4 + 3)

			next

			l_ColorProp.Elements.Array  = l_ColorPropArray

			l_AllInputUVTxtAndCAV.Add l_aColorArray(i)

			l_AllOutputUVTxtAndCAV.Add l_ColorProp

			i = i+2

		Loop

	end if

	if IsArray(l_aMaterialArray) then

		Dim l_bEmptyMaterialIndexArray

		Dim l_CurrentMaterial

		Dim l_NewMaterial

		Dim l_NewCluster

		Dim l_MaxIndex

		Dim l_MaterialIndexArray

		Dim l_Material

		i = 0

		do while i < ubound(l_aMaterialArray)

			set l_NewCluster = l_NewMesh.ActivePrimitive.Geometry.AddCluster(siPolygonCluster, , l_aMaterialArray(i+1))

			MakeLocal l_NewCluster.Material

			CopyPaste l_aMaterialArray(i),,l_NewCluster,2

			SIRebindByNameUserData l_NewCluster.Material, l_AllInputUVTxtAndCAV, l_AllOutputUVTxtAndCAV

			i = i+2

		Loop

	end if

	'Rebind the material that may be a local property at object level

	SIRebindByNameUserData l_NewMesh.Material, l_AllInputUVTxtAndCAV, l_AllOutputUVTxtAndCAV

	SelectObj l_NewMesh

End Sub