Slope3d: Plot results of a Slope analysis of a surface

In molaR: Dental Surface Complexity Measurement Tools

Plot results of a Slope analysis of a surface

Description

A function that produces a three-dimensional rendering of surface slope. The Slope function will identify the slope of each mesh face. It must be performed prior to using the Slope3d function.

Usage

Slope3d(
  Slope_File,
  colors = c("blue", "cornflowerblue", "green", "yellowgreen", "yellow", "orangered",
    "red"),
  maskNegatives = TRUE,
  legend = TRUE,
  main = "",
  cex = 1,
  leftOffset = 1,
  fieldofview = 0,
  fileName = NA,
  binary = FALSE
)

Arguments

Slope_File	An object that stores the output of the Slope function
colors	String of colors to build the color gradient
maskNegatives	Logical indicating whether or not to mask (in black) negative slopes, or to reflect them into positive slopes
legend	Logical indicating whether or not a legend should be displayed
main	String indicating plot title
cex	Numeric setting the relative size of the legend and title
leftOffset	Numeric between -1 and 1 setting the amount of offset for the plotted surface to the left. Larger values push surface farther to right.
fieldofview	Passes an argument to par3d() changing the field of view in degrees of the resulting surface plot
fileName	String indicating a name to save the plotted surface to as a *.ply file; default of 'NA' will not save a file
binary	Logical indicating whether or not the saved surface plot should be binary, passed to vcgPlyWrite()

Details

This function creates a heat map on the mesh surface corresponding to the slope of each face calculated by the Slope function.

Colors are taken as a series inputs to define a color ramp and can be customized indefinitely in value or order. The default is suggested as an intuitive display of increasing color heat corresponding with steeper face slope.

A title can be added to the plot by supplying a character string to the main argument. Title and legend size are controlled with the cex argument, analogous to that in the default R graphics device.

The leftOffset value sets how far to the left the surface will plot, intended to help avoid overlap with the legend. Value of 0 will center the surface and should be invoked if the legend argument is disabled. Higher values will push the surface farther left and negative values will push it to the right. It is recommended that these values be restricted between -1 and 1 to avoid plotting the surface outside of the rgl window.

fieldofview is set to a default of 0, which is an isometric projection. Increasing it alters the degree of parallax in the perspective view, up to a maximum of 179 degrees (see rgl::par3d()).

The plotted, colorized surface can be saved as a *.ply to the working directory by changing the fileName argument from NA to a string (e.g., "SlopePlot"). The resultant ply file can be opened and manipulated in other 3D visualizing programs, such as MeshLab, but will NOT retain its legend (a background of the plotting window). To retain the legend, the user is encouraged to utilize the function 'snapshot3d()' in the rgl package. (see rgl::rgl.snapshot()) The binary argument saves a file in ascii format by default, which is supported by more 3D visualization software than is binary. However, binary files will be considerably smaller.

Examples

Slope_output <- Slope(Tooth)
Slope3d(Slope_output)

molaR documentation built on Feb. 16, 2023, 10:33 p.m.