Graphing an Island as a 3D Surface Plot

posted in: Graphing | 1

GeoSurface_NoAxis1-300x244

This example shows how to graph an island as a 3D surface plot, and to use special contour line to indicate a particular elevation.

Download this OPJ file (2309_GeoSurface_NoAxis.zip, 437KB) to learn how to make this graph.

Create a 3D surface plot from matrix

As you can see in the below image, in the data matrix, the island is represented by positive values and ocean is represented by missing value.

2309_GeoSurface_NoAxis_00

With this data matrix as the active window, you can choose Plot: 3D Surface: Color Map Surface to plot a 3D surface and here is what you will see:
GeoSurface_NoAxis_initial_plot_speed_mode

As you can see in the above image, speed mode will be on for this data by default.  To increase the redraw speed of your graph layer, let’s keep the speed mode be on when you customize the graph with the below steps.

Let’s now customize this graph, by double-clicking to open the Plot Details dialog.

  1. Select the data plot in the left panel and go to the Colormap/Contours tab. In this tab, click the Level… header to open the Set Levels dialog, and apply the settings below:
    2309_GeoSurface_NoAxis_01Click the Fill… header to open the Fill dialog. In the Fill dialog, select Introducing Other Colors in Mixing radio button and set the From and To color as Blue and Red.
    2309_GeoSurface_NoAxis_02
  2. Go to the Mesh tab and deselect the Enable box to disable the mesh line.
  3. Go to the Axis tab, and set the axis lengths as below:
    2309_GeoSurface_NoAxis_03
    You may change the angle of rotation interactively by dragging the mouse, as shown in this video:

Add lighting effect on the graph

You can turn on lighting effect on your surface plot by clicking the yellow light bulb button on the Styles toolbar.

  1. With the 3D graph active, click the button shown below.
    GeoSurface_NoAxis_001
  2. Click on the circular control and move it around to change the direction of the light source, and you can see the surface changes accordingly, as shown in this video:

    3. You can make further changes in the Properties tab as shown below:
    GeoSurface_NoAxis_002

Alternatively, you may also turn on lighting from the Plot Details dialog in the Layer level.

  1. Double-click on the graph to open the Plot Details dialog. Select Layer1 in the left panel and go to the Lighting tab.
  2. Check the Directional in the Mode radio box and change the settings of lights.
    GeoSurface_NoAxis_000

Customize a specified contour line

Next we will make a particular contour level to stand out by making it look different from other levels:

  1. Open the Plot Details dialog. Select the plot in the left panel and go to  Colormap/Contours tab.
  2. Click the contour line at the level of 80 to open the Line dialog and customize settings based on actual demand.
    GeoSurface_NoAxis_003

Hide all three axis planes and three axes

To show the island, we don’t really need the axes, so we should turn them all off:

  1. Open the Plot Details dialog. Select Layer1 in the left panel and go to the Planes tab, then uncheck the XY, YZ and ZX check box.
    GeoSurface_NoAxis_004
  2. Go to Display tab and uncheck the X Axes,  Y Axes and  Z Axes check box under the Show Elements group.
    GeoSurface_NoAxis_005

Turn off speed mode

After customization, if you are satisfied with the graph, you can turn off speed mode using the Speed Mode button indicated in the aubergine circle in the image below :

GeoSurface_NoAxis_speed_mode_button

Alternatively, you can also turn off the Speed Mode in the Plot Details dialog.

GeoSurface_NoAxis_speed_mode_PD

After this, you will get the final graph as shown at the beginning of the blog.

One Response

  1. Xiaolei Bao

    Thanks a lot.

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