vrmlgen (version 1.3)

vmesh: Create 3D mesh and parametric function visualizations in VRML-format

Description

vmesh visualizes 3D meshes and parametric functions in the VRML-format.

Usage

vmesh(infile = NULL, data = NULL, edges = NULL,
xfun = "sin(v)*cos(u)", yfun = "sin(v)*sin(u)",
 zfun = "cos(v)", param1 = "u", param2 = "v",
range1 = c(0,2*pi), range2 = c(0,pi), size1 = 30,
size2 = 30, filename = "out.wrl", cols = "red",
scalefac = 4, autoscale=ifelse(is.null(infile),
"independent","equicenter"), lab.axis = c("X-axis",
"Y-axis", "Z-axis"), col.axis = "white", showaxis = TRUE,
col.lab = "white", col.bg = "black", cex.lab = 1,
navigation = "EXAMINE", transparency = 0, fov = 0.785,
pos = rep(scalefac + 4, 3), dir = c(0.19, 0.45, 0.87, 2.45),
htmlout = NULL, hwidth = 1200, hheight = 800)

Arguments

infile
filename of 3D mesh input file in obj-format (not required if data and edges or the parameters for parametric functions are specified)
data
a numerical matrix with 3 columns and n rows specifying the coordinates of mesh vertices (not used if parameter infile or xfun is specified
edges
a numerical matrix with each row corresponding to the vertex numbers which form a polygon (first vertex has number 0)
xfun
parametric function to define curves and surfaces (1. dimension)
yfun
parametric function to define curves and surfaces (2. dimension)
zfun
parametric function to define curves and surfaces (3. dimension)
param1
name of the first parameter used in parametric functions
param2
name of the second parameter used in parametric functions
range1
value range for the first parameter for parametric functions
range2
value range for the second parameter for parametric functions
size1
mesh size for the first parameter used in parametric functions
size2
mesh size for the second parameter used in parametric functions
filename
filename of the generated VRML output file
cols
a vector of colors to visualize different classes among the data points. The number of colors should be at least as large as the number of different labels (i.e. length(col) >= length(unique(labels))
scalefac
a scaling factor for the size of the 3D box in which the data will be visualized
autoscale
the scaling type. "independent" means all axes are auto-scaled independently, "equidist" means all axes are scaled by the same factor, "equicenter" additionally positions the drawn object in the center, "none" means no scaling is applied
lab.axis
a vector of size 3 containing the axis labels
col.axis
color of the axis
showaxis
if FALSE, the coordinate axes are hidden in the output
col.lab
a vector of colors specifying the axis labels
col.bg
background color
cex.lab
scaling factor for axis label font size
navigation
type of mouse navigation in the VRML file, can be "EXAMINE", "WALK", "SLIDE", "FLY" or "PAN"
fov
a scalar defining the field of view angle in the VRML file in radians
pos
a vector of size 3 for the position of the viewpoint in the VRML coordinate system
transparency
a value between 0 and 1 specifying the degree of transparency for the objects to be drawn
dir
a vector of size 4 specifying the viewing direction (first 3 components) and the rotation of the camera around the direction vector (last component in radians)
htmlout
a filename for generating an HTML-file to embed the VRML-output
hwidth
width of the embedded VRML-display in the HTML-output
hheight
height of the embedded VRML-display in the HTML-output

Value

  • The function is used for its side-effect (output of a VRML-file in the specified directory) and has no return value. The htmlout-parameter can be used to embed the resulting VRML-object in a HTML-file.

Details

There are three ways to use the function: An obj-file in the current directory can be specified as input with the infile-parameter, a 3D mesh can be specified using the data and edges parameter (in both cases, no other parameters are required), or a parametric function can be defined using the xfun, yfun and zfun parameters (in this case, param1, param2, range1 and range2 parameters have to be set additionally). The htmlout-parameter can be used to embed the resulting VRML-object in a HTML-file.

See Also

lmesh

Examples

# Visualization of a parametric function
# defining the surface of 3D spiral
vmesh(xfun="s*cos(s)*(4 + cos(t+s))",
yfun="s*sin(s)*(4 + cos(t+s))",
zfun="s*sin(t+s)",
param1="s", param2="t",
range1=c(0,4*pi), range2=c(0,2*pi))