public Legend Legend { get; set; }

Public Property Legend As Legend

<dxc:Chart3DControl>
    <dxc:Chart3DControl.DataContext>
        <local:SalesChartViewModel/>
    </dxc:Chart3DControl.DataContext>
    <dxc:Chart3DControl.XAxis>
        <dxc:XAxis3D>
            <dxc:XAxis3D.NumericScaleOptions>
                <dxc:ManualNumericScaleOptions/>
            </dxc:XAxis3D.NumericScaleOptions>
        </dxc:XAxis3D>
    </dxc:Chart3DControl.XAxis>
    <dxc:Chart3DControl.Legends>
        <dxc:Legend x:Name="legend"
                    HorizontalPosition="RightOutside"
                    VerticalPosition="Top">
            <dxc:Legend.Title>
                <dxc:LegendTitle Content="DevAV Sales"/>
            </dxc:Legend.Title>
        </dxc:Legend>
    </dxc:Chart3DControl.Legends>
    <dxc:Chart3DControl.SeriesSource>
        <dxc:Series3DStorage>
            <dxc:Series3D DisplayName="Manhattan Bars"
                          Legend="{Binding ElementName=legend}">
                <dxc:Series3D.PointSource>
                            <dxc:SeriesPoint3DDataSourceAdapter DataSource="{Binding SaleData}" 
                                                                XArgumentDataMember="Year"
                                                                YArgumentDataMember="Region" 
                                                                ValueDataMember="Value"/>
                        </dxc:Series3D.PointSource>
                <dxc:Series3D.View>
                    <dxc:Bar3DSeriesView>
                        <dxc:Bar3DSeriesView.Colorizer>
                            <dxc:KeyColorColorizer3D>
                                <dxc:KeyColorColorizer3D.KeyProvider>
                                    <dxc:XArgumentKeyProvider3D/>
                                </dxc:KeyColorColorizer3D.KeyProvider>
                            </dxc:KeyColorColorizer3D>
                        </dxc:Bar3DSeriesView.Colorizer>
                    </dxc:Bar3DSeriesView>
                </dxc:Series3D.View>
            </dxc:Series3D>
        </dxc:Series3DStorage>
    </dxc:Chart3DControl.SeriesSource>
</dxc:Chart3DControl>

public class SaleInfo {
    public int Year { get; }
    public string Region { get; }
    public decimal Value { get; }

    public SaleInfo(int year, string region, decimal value) {
        this.Year = year;
        this.Region = region;
        this.Value = value;
    }
}

class SalesChartViewModel {
    public IReadOnlyList<SaleInfo> SaleData { get; }

    public SalesChartViewModel() {
        int lastYear = DateTime.Now.Year - 1;

        SaleData = new List<SaleInfo> {
            new SaleInfo(lastYear - 2, "Asia", 4.23M),
            new SaleInfo(lastYear - 2, "North America", 3.485M),
            new SaleInfo(lastYear - 2, "Europe", 3.088M),
            new SaleInfo(lastYear - 2, "Australia", 1.78M),
            new SaleInfo(lastYear - 2, "South America", 1.602M),
            new SaleInfo(lastYear - 1, "Asia", 4.768M),
            new SaleInfo(lastYear - 1, "North America", 3.747M),
            new SaleInfo(lastYear - 1, "Europe", 3.357M),
            new SaleInfo(lastYear - 1, "Australia", 1.957M),
            new SaleInfo(lastYear - 1, "South America", 1.823M),
            new SaleInfo(lastYear, "Asia", 5.289M),
            new SaleInfo(lastYear, "North America", 4.182M),
            new SaleInfo(lastYear, "Europe", 3.725M),
            new SaleInfo(lastYear, "Australia", 2.272M),
            new SaleInfo(lastYear, "South America", 2.117M)
        };
    }
}

Public Class SaleInfo
    Public ReadOnly Property Year As Integer
    Public ReadOnly Property Region As String
    Public ReadOnly Property Value As Decimal

    Public Sub New(ByVal year As Integer, ByVal region As String, ByVal value As Decimal)
        Me.Year = year
        Me.Region = region
        Me.Value = value
    End Sub
End Class

Class SalesChartViewModel
    Public ReadOnly Property SaleData As IReadOnlyList(Of SaleInfo)

    Public Sub New()
        Dim lastYear = DateTime.Now.Year - 1

        SaleData = New List(Of SaleInfo) From {
            New SaleInfo(lastYear - 2, "Asia", 4.23D),
            New SaleInfo(lastYear - 2, "North America", 3.485D),
            New SaleInfo(lastYear - 2, "Europe", 3.088D),
            New SaleInfo(lastYear - 2, "Australia", 1.78D),
            New SaleInfo(lastYear - 2, "South America", 1.602D),
            New SaleInfo(lastYear - 1, "Asia", 4.768D),
            New SaleInfo(lastYear - 1, "North America", 3.747D),
            New SaleInfo(lastYear - 1, "Europe", 3.357D),
            New SaleInfo(lastYear - 1, "Australia", 1.957D),
            New SaleInfo(lastYear - 1, "South America", 1.823D),
            New SaleInfo(lastYear, "Asia", 5.289D),
            New SaleInfo(lastYear, "North America", 4.182D),
            New SaleInfo(lastYear, "Europe", 3.725D),
            New SaleInfo(lastYear, "Australia", 2.272D),
            New SaleInfo(lastYear, "South America", 2.117D)
        }
    End Sub
End Class