rgl (version 0.98.22)

mesh3d: 3D Mesh objects

Description

3D triangle and quadrangle mesh object creation and a collection of sample objects.

Usage

qmesh3d(vertices, indices, homogeneous = TRUE, material = NULL, 
         normals = NULL, texcoords = NULL)
  tmesh3d(vertices, indices, homogeneous = TRUE, material = NULL, 
         normals = NULL, texcoords = NULL)
  as.mesh3d(x, ...)
  
  cube3d(trans = identityMatrix(), ...)  
  tetrahedron3d(trans = identityMatrix(), ...)  
  octahedron3d(trans = identityMatrix(), ...)  
  icosahedron3d(trans = identityMatrix(), ...)
  dodecahedron3d(trans = identityMatrix(), ...)
  cuboctahedron3d(trans = identityMatrix(), ...)
  
  oh3d(trans = identityMatrix(), ...)    # an 'o' object
  
  dot3d(x, ...)   # draw dots at the vertices of an object
  # S3 method for mesh3d
dot3d(x, override = TRUE, ...)
  wire3d(x, ...)  # draw a wireframe object
  # S3 method for mesh3d
wire3d(x, override = TRUE, ...)
  shade3d(x, ...) # draw a shaded object
  # S3 method for mesh3d
shade3d(x, override = TRUE, ...)

Arguments

x

a mesh3d object (class qmesh3d or tmesh3d), or for as.mesh3d an object with a method defined.

vertices

3- or 4-component vector of coordinates

indices

4-component vector of vertex indices

homogeneous

logical indicating if homogeneous (four component) coordinates are used.

material

material properties for later rendering

normals

normals at each vertex

texcoords

texture coordinates at each vertex

trans

transformation to apply to objects; see below for defaults

...

additional rendering parameters

override

should the parameters specified here override those stored in the object?

Value

qmesh3d, cube3d, oh3d, tmesh3d, tetrahedron3d, octahedron3d, icosahedron3d and dodecahedron3d return objects of class c("mesh3d", "shape3d"). The first three of these are quad meshes, the rest are triangle meshes.

dot3d, wire3d, and shade3d are called for their side effect of drawing an object into the scene; they return an object ID (or vector of IDs, for some classes) invisibly.

See rgl.primitive for a discussion of texture coordinates.

Details

These functions create and work with mesh3d objects, which consist of a matrix of vertex coordinates together with a matrix of indices indicating which vertex is part of which face. Such objects may have triangular faces, planar quadrilateral faces, or both.

The as.mesh3d function is generic; currently the only method defined is as.mesh3d.deldir.

The sample objects optionally take a matrix transformation trans as an argument. This transformation is applied to all vertices of the default shape. The default is an identity transformation.

The "shape3d" class is a general class for shapes that can be plotted by dot3d, wire3d or shade3d.

The "mesh3d" class is a class of objects that form meshes: the vertices are in member vb, as a 3 or 4 by n matrix. Meshes with triangular faces will contain it, a 3 * n matrix giving the indices of the vertices in each face. Quad meshes will have vertex indices in ib, a 4 * n matrix.

See Also

r3d, par3d, shapelist3d for multiple shapes

Examples

# NOT RUN {
  # generate a quad mesh object

  vertices <- c( 
     -1.0, -1.0, 0, 1.0,
      1.0, -1.0, 0, 1.0,
      1.0,  1.0, 0, 1.0,
     -1.0,  1.0, 0, 1.0
  )
  indices <- c( 1, 2, 3, 4 )
  
  open3d()  
  wire3d( qmesh3d(vertices, indices) )
  
  # render 4 meshes vertically in the current view

  open3d()  
  bg3d("gray")
  l0 <- oh3d(tran = par3d("userMatrix"), color = "green" )
  shade3d( translate3d( l0, -6, 0, 0 ))
  l1 <- subdivision3d( l0 )
  shade3d( translate3d( l1 , -2, 0, 0 ), color = "red", override = FALSE )
  l2 <- subdivision3d( l1 )
  shade3d( translate3d( l2 , 2, 0, 0 ), color = "red", override = TRUE )
  l3 <- subdivision3d( l2 )
  shade3d( translate3d( l3 , 6, 0, 0 ), color = "red" )
  
  # render all of the Platonic solids
  open3d()
  shade3d( translate3d( tetrahedron3d(col = "red"), 0, 0, 0) )
  shade3d( translate3d( cube3d(col = "green"), 3, 0, 0) )
  shade3d( translate3d( octahedron3d(col = "blue"), 6, 0, 0) )
  shade3d( translate3d( dodecahedron3d(col = "cyan"), 9, 0, 0) )
  shade3d( translate3d( icosahedron3d(col = "magenta"), 12, 0, 0) )
# }