Add create volume example showing how to create a hex volume

examples/CMakeLists.txt

@@ -18,6 +18,7 @@ add_executable(create_fill_attributes create_fill_attributes.cpp)
 add_executable(create_tri_mesh create_tri_mesh.cpp)
 add_executable(edit_mesh edit_mesh.cpp)
 add_executable(algebra algebra.cpp)
+add_executable(create_volume_mesh create_volume_mesh.cpp)
 
 target_link_libraries(hello ${CMAKE_DL_LIBS} ultimaille $<$<BOOL:${OpenMP_CXX_FOUND}>:OpenMP::OpenMP_CXX>)
 target_link_libraries(vertex_distances ${CMAKE_DL_LIBS} ultimaille $<$<BOOL:${OpenMP_CXX_FOUND}>:OpenMP::OpenMP_CXX>)
@@ -33,6 +34,7 @@ target_link_libraries(create_fill_attributes ${CMAKE_DL_LIBS} ultimaille $<$<BO
 target_link_libraries(create_tri_mesh ${CMAKE_DL_LIBS} ultimaille $<$<BOOL:${OpenMP_CXX_FOUND}>:OpenMP::OpenMP_CXX>)
 target_link_libraries(edit_mesh ${CMAKE_DL_LIBS} ultimaille $<$<BOOL:${OpenMP_CXX_FOUND}>:OpenMP::OpenMP_CXX>)
 target_link_libraries(algebra ${CMAKE_DL_LIBS} ultimaille $<$<BOOL:${OpenMP_CXX_FOUND}>:OpenMP::OpenMP_CXX>)
+target_link_libraries(create_volume_mesh ${CMAKE_DL_LIBS} ultimaille $<$<BOOL:${OpenMP_CXX_FOUND}>:OpenMP::OpenMP_CXX>)
 
 IF (NOT WIN32)
  target_link_libraries(hello m)
@@ -48,6 +50,7 @@ IF (NOT WIN32)
  target_link_libraries(create_tri_mesh m)
  target_link_libraries(edit_mesh m)
  target_link_libraries(algebra m)
+ target_link_libraries(create_volume_mesh m)
 ENDIF()
 
 # Copy asset files to build directory

examples/create_volume_mesh.cpp

@@ -0,0 +1,64 @@
+/**
+ * This example shows how to create tet/hex volumetric mesh from scratch
+*/
+#include "helpers.h"
+#include <ultimaille/all.h>
+
+
+using namespace UM;
+
+int main(int argc, char** argv) {
+
+ // --- LOAD ---
+
+ // Declare a mesh with hex cells
+ Hexahedra m;
+
+ // --- CREATE ---
+
+ // Create and place 8 points
+ // /!\ There is a vertex numbering convention (https://github.com/ultimaille/ultimaille/tree/master/notes/mesh_vertex_numbering_convention.pdf),
+ // it gives a specific order of vertex to be able to rely them correctly
+ // Here, this order is given by following points declaration
+ // Therefore, we just have to associate vertex i with point i (m.vert(0,i) = i)
+ // Note that we could have declared them in any order, but if we did, we'd have to link them in the right order
+ m.points.create_points(8);
+ m.points[0] = vec3(-0.5,-0.5,-0.5);
+ m.points[1] = vec3(0.5,-0.5,-0.5);
+ m.points[2] = vec3(-0.5,0.5,-0.5);
+ m.points[3] = vec3(0.5,0.5,-0.5);
+ m.points[4] = vec3(-0.5,-0.5,0.5);
+ m.points[5] = vec3(0.5,-0.5,0.5);
+ m.points[6] = vec3(-0.5,0.5,0.5);
+ m.points[7] = vec3(0.5,0.5,0.5);
+
+ // Create 1 cell
+ m.create_cells(1);
+ // Link cell 0, vertex 0 with point 0
+ m.vert(0, 0) = 0;
+ // Link cell 0, vertex 1 with point 1
+ m.vert(0, 1) = 1;
+ // ...
+ m.vert(0, 2) = 2;
+ m.vert(0, 3) = 3;
+ m.vert(0, 4) = 4;
+ m.vert(0, 5) = 5;
+ m.vert(0, 6) = 6;
+ m.vert(0, 7) = 7;
+
+ // --- SAVE ---
+
+ // Save mesh
+ write_by_extension("hex_mesh.geogram", m, {{}, {}, {}});
+
+ // --- END ---
+
+ // --- RUN ---
+
+ #ifdef _WIN32
+ // Open the generated mesh with Graphite
+ int result = system((getGraphitePath() + " hex_mesh.geogram").c_str());
+ #endif
+
+ return 0;
+}