Applies to: Nevron Chart for .NET
Triangulated Surface Chart is not displaying
Q: I am generating data to display a Triangulated Surface chart. However, this specific set of data produces empty chart area and the Triangulated Surface is not displayed. What may be causing this?
A: In some cases, geometric calculations that are based on floating point arithmetic return incorrect results (due to the limited precision of FP arithmetic). This spoils the logic of the triangulation algorithm and it fails to produce a result. This is most likely to happen when the input set of points forms a regular structure in the XZ plane - like for example a grid or a circle. Such input sets are considered degenerate for triangulation algorithms.
You will have to set the UsePreciseGeometry property to true. When the UsePreciseGeometry property, the triangulation uses more precise calculations. This makes the algorithm robust, but at a certain performance cost. If possible, you can also use mesh surface series instead of triangulated surface.
Following is an example for creating a Triangulated Surface chart with UsePreciseGeometry property set to true:
[C#]
using System;
using System.Windows.Forms;
using Nevron.Chart;
using Nevron.Chart.WinForm;
using Nevron.GraphicsCore;
...
private void Form1_Load(object sender, EventArgs e)
{
nChartControl1.Controller.Tools.Add(new NSelectorTool());
nChartControl1.Controller.Tools.Add(new NTrackballTool());
NCartesianChart chart = (NCartesianChart)nChartControl1.Charts[0];
chart.Enable3D = true;
chart.Width = 55;
chart.Depth = 55;
chart.Height = 30;
chart.Projection.Type = ProjectionType.Perspective;
chart.Projection.Elevation = 30;
chart.Projection.Rotation = -60;
chart.LightModel.SetPredefinedLightModel(PredefinedLightModel.NorthernLights);
NTriangulatedSurfaceSeries triangulatedSurface = new NTriangulatedSurfaceSeries();
chart.Series.Add(triangulatedSurface);
triangulatedSurface.UsePreciseGeometry = true;
triangulatedSurface.FrameMode = SurfaceFrameMode.Mesh;
for (int j = 0; j < 30; j++)
{
for (int i = 0; i < 30; i++)
{
double yPoint = Math.Sin(i * 0.1) * Math.Cos(j * 0.1);
triangulatedSurface.XValues.Add(i);
triangulatedSurface.ZValues.Add(j);
triangulatedSurface.Values.Add(yPoint);
}
}
}
[VB.NET]
Imports System
Imports System.Windows.Forms
Imports Nevron.Chart
Imports Nevron.Chart.WinForm
Imports Nevron.GraphicsCore
...
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
NChartControl1.Controller.Tools.Add(New NSelectorTool())
NChartControl1.Controller.Tools.Add(New NTrackballTool())
Dim chart As NCartesianChart = DirectCast(NChartControl1.Charts(0), NCartesianChart)
chart.Enable3D = True
chart.Width = 55
chart.Depth = 55
chart.Height = 30
chart.Projection.Type = ProjectionType.Perspective
chart.Projection.Elevation = 30
chart.Projection.Rotation = -60
chart.LightModel.SetPredefinedLightModel(PredefinedLightModel.NorthernLights)
Dim triangulatedSurface As New NTriangulatedSurfaceSeries()
chart.Series.Add(triangulatedSurface)
triangulatedSurface.UsePreciseGeometry = True
triangulatedSurface.FrameMode = SurfaceFrameMode.Mesh
For j As Integer = 0 To 29
For i As Integer = 0 To 29
Dim yPoint As Double = Math.Sin(i * 0.1) * Math.Cos(j * 0.1)
triangulatedSurface.XValues.Add(i)
triangulatedSurface.ZValues.Add(j)
triangulatedSurface.Values.Add(yPoint)
Next
Next
End Sub
Article ID: 141, Created On: 11/25/2010, Modified: 12/1/2010