unreal custom node to compute uv

unreal wold position uv node.txt

Begin Object Class=/Script/UnrealEd.MaterialGraphNode Name="MaterialGraphNode_19" ExportPath="/Script/UnrealEd.MaterialGraphNode'/Engine/Transient.PreviewMaterial_0:MaterialGraph_0.MaterialGraphNode_19'"
   Begin Object Class=/Script/Engine.MaterialExpressionCustom Name="MaterialExpressionCustom_0" ExportPath="/Script/Engine.MaterialExpressionCustom'/Engine/Transient.PreviewMaterial_0:MaterialGraph_0.MaterialGraphNode_19.MaterialExpressionCustom_0'"
   End Object
   Begin Object Name="MaterialExpressionCustom_0" ExportPath="/Script/Engine.MaterialExpressionCustom'/Engine/Transient.PreviewMaterial_0:MaterialGraph_0.MaterialGraphNode_19.MaterialExpressionCustom_0'"
      Code="\r\nfloat4 NDCPosition = LWCMultiply(MakeLWCVector4(LWCWorldPosition, 1.0f), ResolvedView.WorldToClip);\r\nNDCPosition.xy /= NDCPosition.w;\r\nfloat2 uv = NDCPosition.xy * float2(0.5f, -0.5f) + 0.5f;\r\nreturn uv;\r\n"
      OutputType=CMOT_Float2
      Description="ComputeUV"
      Inputs(0)=(InputName="WorldPosition",Input=(Expression="/Script/Engine.MaterialExpressionDoubleVectorParameter'MaterialExpressionDoubleVectorParameter_0'",Mask=1,MaskR=1,MaskG=1,MaskB=1))
      MaterialExpressionEditorX=-1408
      MaterialExpressionEditorY=-240
      MaterialExpressionGuid=DF2193264A3683C106038A9830BB12F7
      Material="/Script/UnrealEd.PreviewMaterial'/Engine/Transient.PreviewMaterial_0'"
      Desc="ComputeWorldPositionUV"
      bCommentBubbleVisible=True
   End Object
   MaterialExpression="/Script/Engine.MaterialExpressionCustom'MaterialExpressionCustom_0'"
   NodePosX=-1408
   NodePosY=-240
   bCommentBubbleVisible=True
   NodeComment=""
   NodeGuid=052BB60440306001941CE1A792BBF5F6
   CustomProperties Pin (PinId=616D7F3F49AEF8F394DEB987A5649874,PinName="WorldPosition",PinType.PinCategory="required",PinType.PinSubCategory="",PinType.PinSubCategoryObject=None,PinType.PinSubCategoryMemberReference=(),PinType.PinValueType=(),PinType.ContainerType=None,PinType.bIsReference=False,PinType.bIsConst=False,PinType.bIsWeakPointer=False,PinType.bIsUObjectWrapper=False,PinType.bSerializeAsSinglePrecisionFloat=False,LinkedTo=(MaterialGraphNode_18 C16BA6A0411BD7C9828F5F8523E0CAE8,),PersistentGuid=00000000000000000000000000000000,bHidden=False,bNotConnectable=False,bDefaultValueIsReadOnly=False,bDefaultValueIsIgnored=False,bAdvancedView=False,bOrphanedPin=False,)
   CustomProperties Pin (PinId=14F9773F4199662A1A702494A67273A5,PinName="Output",PinFriendlyName=NSLOCTEXT("MaterialGraphNode", "Space", " "),Direction="EGPD_Output",PinType.PinCategory="",PinType.PinSubCategory="",PinType.PinSubCategoryObject=None,PinType.PinSubCategoryMemberReference=(),PinType.PinValueType=(),PinType.ContainerType=None,PinType.bIsReference=False,PinType.bIsConst=False,PinType.bIsWeakPointer=False,PinType.bIsUObjectWrapper=False,PinType.bSerializeAsSinglePrecisionFloat=False,LinkedTo=(MaterialGraphNode_16 CBD311F4473ACFC86B30CA8A8E07A724,),PersistentGuid=00000000000000000000000000000000,bHidden=False,bNotConnectable=False,bDefaultValueIsReadOnly=False,bDefaultValueIsIgnored=False,bAdvancedView=False,bOrphanedPin=False,)
End Object

world position is set by calling in c++ UMaterialInstanceDynamic::SetDoubleVectorParameterValue