Stacked Mountains are provided by the StackedMountainRenderableSeries type. This shares many of the properties with the FastMountainRenderableSeries type, with the added feature that mountains automatically stack (aggregate Y-values).

To declare a StackedMountainRenderableSeries, use the following code:

Declare a StackedMountainRenderableSeries in Xaml / Code Behind

<Grid>
       <Grid.Resources>
             <LinearGradientBrush x:Key="chartFill1" StartPoint="0,0" EndPoint="0,1">
                    <GradientStop Offset="0" Color="#DDDBE0E1" />
                    <GradientStop Offset="1.0" Color="#88B6C1C3" />
             </LinearGradientBrush>

             <LinearGradientBrush x:Key="chartFill0" StartPoint="0,0" EndPoint="0,1">
                    <GradientStop Offset="0" Color="#DDACBCCA" />
                    <GradientStop Offset="1.0" Color="#88439AAF" />
             </LinearGradientBrush>
       </UserControl.Resources>

       <!--  Create the chart surface  -->
       <s:SciChartSurface Name="sciChart">

             <!--  Declare RenderableSeries  -->
             <s:SciChartSurface.RenderableSeries>
                    <s:StackedMountainRenderableSeries x:Name="mountainSeries1"
                           Fill="{StaticResource chartFill0}"
                           Stroke="#EEE"                                                             StrokeThickness="2" />
                    <s:StackedMountainRenderableSeries x:Name="mountainSeries2"
                           Fill="{StaticResource chartFill1}"
                           Stroke="#EEE"
                           StrokeThickness="2" />
             </s:SciChartSurface.RenderableSeries>

             <!--  Create an X Axis  -->
             <s:SciChartSurface.XAxis>
                    <s:NumericAxis/>
             </s:SciChartSurface.XAxis>

             <!--  Create a Y Axis with GrowBy  -->
             <s:SciChartSurface.YAxis>
                    <s:NumericAxis/>
             </s:SciChartSurface.YAxis>

       </s:SciChartSurface>
</Grid>

// Code Behind, e.g. in OnLoaded event handler, set the DataSeries
var yValues1 = new[] { 4.0, 7,  5.2,  9.4,  3.8,  5.1, 7.5,  12.4 };
var yValues2 = new[] { 15.0, 10.1, 10.2, 10.4, 10.8, 1.1, 11.5, 3.4 };

var dataSeries1 = new XyDataSeries<double, double>() { SeriesName = "data1" };
var dataSeries2 = new XyDataSeries<double, double>() { SeriesName = "data2" }; ;

for (int i = 0; i < yValues1.Length; i++) dataSeries1.Append(i, yValues1[i]);
for (int i = 0; i < yValues2.Length; i++) dataSeries2.Append(i, yValues2[i]);

using (this.sciChart.SuspendUpdates())
{
       this.mountainSeries1.DataSeries = dataSeries1;
       this.mountainSeries2.DataSeries = dataSeries2;
}

Declare a StackedMountainRenderableSeries in Pure Code

var sciChartSurface = new SciChartSurface();
// Assumes X,y Axis have been declared
var mountainSeries1 = new StackedMountainRenderableSeries()
{
       StrokeThickness = 2,
       AntiAliasing = true,
       Stroke = Color.FromArgb(0xFF, 0xAA, 0xAA, 0xAA),
       Fill = new SolidColorBrush(Colors.LightSteelBlue),
       ZeroLineY = 0.0,
};
var mountainSeries2 = new StackedMountainRenderableSeries()
{
       StrokeThickness = 2,
       AntiAliasing = true,
       Stroke = Color.FromArgb(0xFF, 0xAA, 0xAA, 0xAA),
       Fill = new SolidColorBrush(Colors.LightSteelBlue),
       ZeroLineY = 0.0,
};
sciChartSurface.RenderableSeries.Add(mountainSeries1);
sciChartSurface.RenderableSeries.Add(mountainSeries2);

var yValues1 = new[] { 4.0,  7,    5.2,  9.4,  3.8,  5.1, 7.5,  12.4, 14.6, 8.1, 11.7, 14.4, 16.0, 3.7, 5.1, 6.4, 3.5, 2.5, 12.4, 16.4, 7.1, 8.0, 9.0 };
var yValues2 = new[] { 15.0, 10.1, 10.2, 10.4, 10.8, 1.1, 11.5, 3.4,  4.6,  0.1, 1.7, 14.4, 6.0, 13.7, 10.1, 8.4, 8.5, 12.5, 1.4, 0.4, 10.1, 5.0, 0.0 };

var dataSeries1 = new XyDataSeries<double, double>() { SeriesName = "data1" };
var dataSeries2 = new XyDataSeries<double, double>() { SeriesName = "data2" }; ;

for (int i = 0; i < yValues1.Length; i++) dataSeries1.Append(i, yValues1[i]);
for (int i = 0; i < yValues2.Length; i++) dataSeries2.Append(i, yValues2[i]);

using (this.sciChart.SuspendUpdates())
{
       mountainSeries1.DataSeries = dataSeries1;
       mountainSeries2.DataSeries = dataSeries2;
}

How the Stacking and Grouping Works for Mountain Series

StackedMountainRenderableSeries has a property StackedGroupId which defines how mountains/areas are grouped and stacked. When two StackedMountainRenderableSeries have a StackedGroupId set the mountains behave differently. Some examples below to help visualize this feature.

e.g.

Two Mountains, same (or Unset) StackedGroupID (the default)

By default, the StackedGroupId is null. When this is unset, or, when set to the same value, mountains stack vertically

Orange = no StackedGroupId, Blue = no StackedGroupId

Two Mountains, different StackedGroupId

When the StackedGroupID is different on two mountains, then the mountains are grouped. This allows you to have multiple stacked groups.

Orange = StackedGroupId A, Blue = StackedGroupId B

Three Columns, (2 with one StackedGroupId, 1 with another StackedGroupId)

To demonstrate the purpose of StackedGroupId, below we have set one mountain to one StackedGroupId, and two other mountains to another StackedGroupId. This creates two stacked groups, one with Orange/Red series (which have the same StackedGroupID) and another with the blue series.

Orange, Red = StackedGroupID A, Blue = StackedGroupID B

Limitations of Stacked Series

When using any Stacked Series type, there are a few important limitations to keep in mind to ensure correct rendering and behavior:

1. Consistent X-Values Across Series
   All series within a stacking group must share the same X-values – meaning the collections must be of equal length and contain identical values in the same order. This requirement ensures that columns are stacked properly and aligned accurately on the X-axis
2. X-Values Must Be Valid Numeric Values
   The X-values used in stacked column charts must be valid, finite numeric values. Special values such as Double.NaN, Double.PositiveInfinity, or Double.NegativeInfinity are not supported and will lead to undefined behavior or rendering issues
3. Representing Gaps in Series
   If you need to represent missing data or create gaps in individual series (e.g., when one series has fewer data points than the others), assign Double.NaN or Float.NaN to the corresponding Y-values instead. This tells SciChart to omit rendering the column at that position while preserving the required structure of matching X-values across the group