Graph Surface (3D)
This Select Color Gradient for Surface or Contour option is available to all of the program's 3D surface graphs. There are four basic types of graphs, a wire-frame plot, a mesh plot, gradient plots, and shaded plots.
A wire-frame graph draws the surface by a continuous series of lines. Hidden lines are not removed. This is by far the fastest and simplest plot, but is of limited usefulness in serious surface-fitting work. The color of the wire can be modified via the Wire Line item in the 3D Graph Customize Colors option.
A mesh plot draws the 3D surface by a series of filled polygons drawn from back to front. Hidden lines are removed in this type of plot. The color of the mesh line and the color of the mesh fill can be modified by the Mesh Line and Mesh Fill items in the 3D Graph Customize Colors option.
The gradient spectrum plots include:
100 Spec R->B
100 Spec B->R
128 Spec Rev
Linear (user defined)
Spectral (user defined)
In these plots, the Z-range of the graph is mapped to a gradient of colors and the polygons are drawn within this overall gradient.
A gradient plot will involve drawing a significantly larger number of polygons, and as such, gradient plots are the slowest in the program and the most computationally demanding.
Only the colors within the Linear and Spectral options are adjustable. The Linear option linearly interpolates between the boundary colors based upon their red, green, and blue (RGB) values. The Spec option linearly interpolates between the colors based upon their hue, saturation, and brightness values. To change the color on each bound of the adjustable gradients, click on the color shown to select the color desired.
The 24 Spectrum gradient is available in a custom palette which use exact colors contained within the palettes defined by Excel in 256 color mode. This enables you to paste an The Platform 3D plot into a spreadsheet and have exactly the same colors as the 24 used by The Platform. Note that this option is of value only in 256 color mode. In higher color modes, the spreadsheets should adequately render all colors within the spectrum plots.
In a shaded plot, the brightness of each mesh element is adjusted for the spectral illumination that would be produced by the light source specified in the 3D Graph View option. This light source is specified by angular shifts from the main view angles. The default XY angular shift of +30 degrees and Z angular shift of +15 degrees is similar to holding a point source of illumination above and to the right of the viewer. Shaded plots are faster than gradient plots since the number of polygons to be drawn is no higher than that of a standard mesh plot.
The available shaded plots are:
The color bounds within the User option are adjustable. This option linearly interpolates between the boundary colors based upon their RGB values. To change the color on each bound of the adjustable shading, click on the color shown to select the color desired.
With the large number of colors present in the gradient and shaded plots, it is possible that conflicts will arise with the various colors used in data points, drop lines, and other elements in the graphs. You should use the 3D Graph Customize Colors option to design graph elements that work well with the particular gradient of colors you choose for the surface.
The Reset button restores the program's default 128 Spectrum plot.