inst/essais/essai_fiveTetrahedra2.R

In stla/RCGAL: An Incomplete Wrapper of the 'CGAL' C++ Library

library(rgl)

phi <- (1+sqrt(5))/2
a <- 1/sqrt(3)
b <- a/phi
c <- a*phi

vertices <-
  rbind(
    c( a,  a,  a),
    c( a,  a, -a),
    c( a, -a,  a),
    c(-a, -a,  a),
    c(-a,  a, -a),
    c(-a,  a,  a),
    c( 0,  b, -c),
    c( 0, -b, -c),
    c( 0, -b,  c),
    c( c,  0, -b),
    c(-c,  0, -b),
    c(-c,  0,  b),
    c( b,  c,  0),
    c( b, -c,  0),
    c(-b, -c,  0),
    c(-b,  c,  0),
    c( 0,  b,  c),
    c( a, -a, -a),
    c( c,  0,  b),
    c(-a, -a, -a)
  )
vertices <- round(vertices, 11)

vs1 <- vertices[c(17, 14, 2, 11), ]
vs2 <- vertices[c(18, 1, 4, 5), ]
vs3 <- vertices[c(19, 6, 15, 7), ]
vs4 <- vertices[c(3, 13, 12, 8), ]
vs5 <- vertices[c(20, 16, 10, 9), ]

faces <- rbind(
  c(1, 2, 3),
  c(3, 2, 4),
  c(4, 2, 1),
  c(1, 3, 4)
)
lfaces <- lapply(1:nrow(faces), function(i) as.integer(faces[i, ]-1))
lfacescopy = lapply(lfaces, identity)

mesh1 <- list(
  vertices = t(vs1),
  faces = lfaces
)
mesh2 <- list(
  vertices = t(vs2),
  faces = lfaces
)
mesh3 <- list(
  vertices = t(vs3),
  faces = lfacescopy
)
mesh4 <- list(
  vertices = t(vs4),
  faces = lfaces
)
mesh5 <- list(
  vertices = t(vs5),
  faces = lfaces
)

ii <- RCGAL:::Intersection2_K(
  list(mesh1, mesh2, mesh3),
  FALSE, FALSE
)

vv = ii$vertices
ff = lapply(ii$faces, function(x) x-1L)
mm = list(vertices = vv, faces = ff)
iii <- RCGAL:::Intersection2_K(
  list(
    mesh3,
    mesh4,
    mesh5
  ),
  FALSE, FALSE
)
vv = iii$vertices
ff = lapply(iii$faces, function(x) x-1L)
mmm = list(vertices = vv, faces = ff)

iiii <- RCGAL:::Intersection2_K(
  list(
    mm,
    mmm
  ),
  FALSE, FALSE
)
stop("ooo")
edg <- t(iiii$edges[1:2, iiii$edges[3,]==1])
plotEdges(t(iiii$vertices), edg)

library(RCGAL)
mesh <- Mesh(
  t(iiii[["vertices"]]),
  iiii[["faces"]],
  triangulate = FALSE, merge=TRUE, normals = FALSE, epsilon = 5e-10
)
plotEdges(mesh$vertices, mesh$exteriorEdges)

hull <- cxhull::cxhullEdges(mesh$vertices)
plotEdges(mesh$vertices, hull$edges)

tmesh <- tmesh3d(
  vertices = iiii$vertices,
  indices = do.call(cbind, lapply(iiii$faces, function(x) x+0L)),
  homogeneous = FALSE
)
t1 <- tmesh3d(
  vertices = mesh1$vertices,
  indices = t(faces),
  homogeneous = FALSE
)
t2 <- tmesh3d(
  vertices = mesh2$vertices,
  indices = t(faces),
  homogeneous = FALSE
)
t3 <- tmesh3d(
  vertices = mesh3$vertices,
  indices = t(faces),
  homogeneous = FALSE
)
t4 <- tmesh3d(
  vertices = mesh4$vertices,
  indices = t(faces),
  homogeneous = FALSE
)
t5 <- tmesh3d(
  vertices = mesh5$vertices,
  indices = t(faces),
  homogeneous = FALSE
)
# vcgOffWrite(t1, "th1.off")
# vcgOffWrite(t2, "th2.off")
# vcgOffWrite(t3, "th3.off")
# vcgOffWrite(t4, "th4.off")
# vcgOffWrite(t5, "th5.off")


open3d()
shade3d(t3, color = "cyan", alpha = 0.2)
shade3d(t2, color = "palegreen", alpha = 0.4)
shade3d(t4, color = "yellow", alpha = 0.2)

shade3d(tmesh, color="red")
#plotEdges(t(ii$vertices), t(ii$edges0))
wire3d(tmesh, lwd=3)