When the "Plot 3-D" button is pressed on the "2-D Spectral Analysis Results" window, the "3-D Spectral analysis Results" window is called and a "Scatter Plot" is automatically generated. The user could then generate "Surface Plots" of a desired quantity by pressing the corresponding buttons of the Z-axis. A more detailed description is included below.

The scatter plot is the plot that's created when the window is first opened. It's a 3-D representation of the in the 2-D window. The data is copied into a 3-D chart, by making the series the Y depth of the data. Any plot could be made into a .

Figure 1: Scatter Plot of Displacement (constant strength) for different "Normalized Strengths" and different "Periods"

After the surface plot is displayed, the user can choose to plot any of the quantities on the Z-axis vs. the two variable parameters as the X and Y axes. The resulting chart is a 3-D surface plot that's color zoned depending on the Z value of the points.

Figure 2: Surface Plot showing Displacement against "Ducitility" and "Period" (Constant Ducility)

The 3D dialog has many controls to customize how the data is plot and how the chart looks. The following outlines those controls.

Only one of X,Y and Z constraint can be checked at a time. When the user interactively tries to rotate the chart, if one of the constraints is checked, the chart would rotate about the checked axis.

Four edit boxes that serve as both input and output boxes. They allow the user to enter the view perspective and rotations and see the results. In addition, if the user rotates the chart using the mouse, those boxes updated with the new values.

The "Perspective" box defines the perspective of the view. This value should be larger than 1. A value of 1 gives maximum perspective effect, while a large number removes all perspective effects.

X Rotation is the rotation around the horizontal axis of the screen

Y Rotation is the rotation around the axis perpendicular to the screen

Z Rotation is the rotation around the vertical axis of the screen

This includes an "Auto" checkbox and two edit boxes, for the minimum and maximum limits on the z-axis. When Auto is ON, the chart automatically determines the minimum and maximum limits on the axis, and updates the edit boxes. When checked OFF, the chart limits will be determined by the values entered by the user for minimum and maximum. The chart goes back to Auto when a new plot is generated.

Three checkboxes for: Direction 1, Direction 2 and Resultant (Maximum combination of both directions). Only Direction 1 is available for 1-D analysis. Only one of the three selections can be picked.

Specifies whether the top (ceiling) or bottom (floor) of the plot has contour lines.

Specifies whether the top (ceiling) or bottom (floor) of the plot has contour colors.

Can be either "Cube" or "Full". Determines whether the chart regenerates during rotation (Full) or whether only the outline of the plot cube is shown (Cube). When the window is created, this is usually On, unless the number of points is more than 1000, in which case it's set to Off to avoid excessive generation time.

Three checkboxes to select whether to turn gridlines On or Off on the three planes: XY, XZ, YZ.

Specifies whether the top (ceiling) or bottom (floor) of the plot has contour colors.