bregions! without args and kwargs takes all boundaries instead of none.

Author: j-fu

examples/examples2d.jl

@@ -248,6 +248,22 @@ end
 # ![](swiss_cheese_2d.png)
 #
 
+
+# ## Remeshing another grid
+#
+# The `bregions!` method allows to use another grid as geometry description
+# 
+function remesh_2d()
+    b = SimplexGridBuilder(; Generator = Triangulate)
+    X=0:0.1:1
+    grid1 = simplexgrid(X, X)
+    bregions!(b,grid1)
+    simplexgrid(b,maxvolume=0.01)
+end
+#
+# ![](remesh_2d.png)
+#
+
 # ## Glueing in another grid
 #
 # The `bregions!` method allows to extract parts of the geometry description from
@@ -327,6 +343,9 @@ function generateplots(picdir; Plotter = nothing)
         p = builderplot(swiss_cheese_2d(); Plotter, size)
         Plotter.save(joinpath(picdir, "swiss_cheese_2d.png"),p)
 
+        p = gridplot(remesh_2d(); Plotter, size)
+        Plotter.save(joinpath(picdir, "remesh_2d.png"),p)
+
         p = gridplot(glue_2d(); Plotter, size)
         Plotter.save(joinpath(picdir, "glue_2d.png"),p)
     end

examples/examples3d.jl

@@ -85,6 +85,25 @@ end
 
 # ![](tet_cube_with_primitives.png)
 
+
+
+# ## Remeshing another grid
+#
+# The `bregions!` method allows to use another grid as geometry description
+# 
+function remesh_3d()
+    b = SimplexGridBuilder(; Generator = TetGen)
+    X=0:0.1:1
+    grid1 = simplexgrid(X, X, X)
+    bregions!(b,grid1)
+    simplexgrid(b,maxvolume=0.0001)
+end
+#
+# ![](remesh_3d.png)
+#
+
+
+
 # ## Glue-in of existing grid
 #
 # The [`bregions!`](@ref) method allows to extract parts of the geometry description from
@@ -152,6 +171,10 @@ function generateplots(picdir; Plotter = nothing)
         gridplot(glue_3d(); Plotter, size, azim = 0, elev = 15, xplanes = [5])
         Plotter.savefig(joinpath(picdir, "glue_3d.png"))
 
+        Plotter.clf()
+        gridplot(remesh_3d(); Plotter, size, zplanes = [0.5])
+        Plotter.savefig(joinpath(picdir, "remesh_3d.png"))
+       
         Plotter.clf()
         gridplot(stl_3d(); Plotter, size, xplanes = [5])
         Plotter.savefig(joinpath(picdir, "stl_3d.png"))

src/primitives.jl

@@ -20,7 +20,7 @@ bregions!(builder::SimplexGridBuilder,grid, pairs...)
 ```
 Add  boundary facets of `grid`  with region numbers mentioned as first element in `pairs`
 with region number mentioned as second element of `pairs` to the geometry description. 
-
+If no pairs are given, add  all boundary facets of `grid`  with their original region numbers to builder.
 
 Example:
 
@@ -29,9 +29,16 @@ bregions!(builder,grid, 1=>2, 3=>5)
 ```
 """
 function bregions!(builder::SimplexGridBuilder, grid, pairs...)
-    bregions!(builder, grid, first.([pairs...]); facetregions = last.([pairs...]))
+    if length([pairs...])>0
+        bregions!(builder, grid, first.([pairs...]); facetregions = last.([pairs...]))
+    else
+        cr=unique(grid[BFaceRegions])
+        bregions!(builder, grid, cr; facetregions=cr)
+    end
 end
 
+
+
 """
 ```
 bregions!(builder::SimplexGridBuilder,grid,regionlist;facetregions=nothing)