Perform boolean operations on meshes in RvtkStatismo
19 Feb 2016Due to the wrappers in RvtkStatismo for meshes from R to vtkPolyData, extending the functionality of this package is quite easy. Recently, I added the functionality to perform boolean operations on triangular meshes using the new function vtkBooleanOp.
It creates Unions, Intersections and Differences from two triangular meshes stored in R as objects of class mesh3d.
For creating intersection planes based on an object’s bounding box, the function BBoxSliceswas added to mesheR.
As usual, here is some example code, ready to be run in an R:
Example 1: create the union of two spheres (Figure 1)
require(Rvcg);require(Morpho);require(rgl)
require(RvtkStatismo)
## create two unit spheres
sphere1 <- vcgSphere()
sphere2 <- vcgSphere()
## translate sphere2 by half its radius
sphere2 <- translate3d(sphere2,0,0,0.5)
union <- vtkBooleanOp(sphere1,sphere2)
## create normals for smooth rendering
union <- vcgUpdateNormals(union)
shade3d(union,alpha=0.5,col=2)
wire3d(union)
Example 2: crop a mesh by a bounding box slice (Figure 2 and Figure 3)
require(Rvcg)
require(rgl)
require(mesheR)
sphere <- vcgSphere()
## get corners of the bounding box
bbox <- getMeshBox(sphere,pca=FALSE)
## get a triangular mesh consisting of 3 triangles cutting a slice from the y-z plane
slice <- BBoxSlices(bbox,axis = 1,percent = 0.7)
myplot <- plot3d(sphere,col="white")
shade3d(slice,col=2,alpha=0.5)
## now use the slice to get the difference
cuthead <- vtkBooleanOp(sphere,slice,type=2)
## create normals for smooth rendering
cuthead <- vcgUpdateNormals(cuthead)
shade3d(cuthead,col="white")
