Improvement: Mesh handle tutorials by Vyp3er · Pull Request #2348 · DLR-AMR/t8code

Vyp3er · 2026-06-22T08:40:12Z

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codecov · 2026-07-01T09:48:30Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 82.28%. Comparing base (66cd94f) to head (7b316f3).
⚠️ Report is 6 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2348   +/-   ##
=======================================
  Coverage   82.28%   82.28%           
=======================================
  Files         125      125           
  Lines       20701    20701           
=======================================
  Hits        17033    17033           
  Misses       3668     3668

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lenaploetzke

Partial review. Thank you for your work, this is really nice and my comments are mainly documentation! :)

lenaploetzke · 2026-07-16T10:03:45Z

+  sc_MPI_Comm comm = sc_MPI_COMM_WORLD;
+
+  /* Print a starting message. */
+  t8_global_productionf (" [tutorial] \n");


We should also think of something different than "tutorial" here. Any ideas?

Co-authored-by: lenaploetzke <70579874+lenaploetzke@users.noreply.github.com>

lenaploetzke

Review adapt callback file

lenaploetzke · 2026-07-20T14:24:12Z

@@ -21,18 +21,26 @@
 */

 /** \file t8_mesh_element_data.cxx
- * This is the same as general/t8_step5_element_data.cxx but using the mesh handle interface instead of the forest
+ * This is step5 of the t8code tutorials.
+ * Therefor, this is the same as general/t8_step5_element_data.cxx but using the mesh handle interface instead of the forest


Suggested change

* Therefor, this is the same as general/t8_step5_element_data.cxx but using the mesh handle interface instead of the forest

* Therefore, this is the same as general/t8_step5_element_data.cxx but using the mesh handle interface instead of the forest

lenaploetzke · 2026-07-20T14:24:35Z

@@ -21,18 +21,26 @@
 */

 /** \file t8_mesh_element_data.cxx
- * This is the same as general/t8_step5_element_data.cxx but using the mesh handle interface instead of the forest
+ * This is step5 of the t8code tutorials.


Suggested change

* This is step5 of the t8code tutorials.

* This is step5 of the mesh handle tutorials.

lenaploetzke · 2026-07-20T14:30:11Z

+#include <mesh_handle/mesh.hxx>            /** General Mesh header. Always needed for mesh_handle code. */
+#include <mesh_handle/competence_pack.hxx> /** Competence Pack for basic mesh_handle features. Look into tutorials/mesh_handle/t8_mesh_competences for more information. */
+#include <mesh_handle/constructor_wrappers.hxx> /** Wrapper for basic Cmesh to mesh_handle conversions. */
+#include <mesh_handle/mesh_io.hxx>              /** Used to export mesh to vtk files. */
 #include <mesh_handle/concepts.hxx>


Suggested change

#include <mesh_handle/concepts.hxx>

#include <mesh_handle/concepts.hxx>/** Include this to use c++ concepts related to the mesh handle. This can be used to constraint the template parameters to only allow mesh handle classes. */

Could you also add this to other tutorials where needed?

lenaploetzke · 2026-07-20T14:34:32Z

@@ -100,7 +73,7 @@ build_mesh (sc_MPI_Comm comm, int level)
  mesh_handle->set_balance ();
  mesh_handle->set_partition ();
  mesh_handle->set_adapt (
-    TMeshClass::template mesh_adapt_callback_wrapper<user_data> (adapt_callback<TMeshClass>, adapt_data));
+    TMeshClass::template mesh_adapt_callback_wrapper<adapt_data> (&default_adapt_callback<TMeshClass>, adapt_params));


Could you please explain shortly why the & is valid here? :) I am not saying that it is wrong, just wondering why i left it out and why it is fine this way.

lenaploetzke · 2026-07-20T14:35:30Z

+  sc_MPI_Comm comm = sc_MPI_COMM_WORLD;
+
+  /* Print a starting message. */
+  t8_global_productionf (" [tutorial] \n");


This [tutorial] is not good. Maybe [Step 3 Mesh handle]?

Please also adapt this in all other tutorials

lenaploetzke · 2026-07-21T11:04:14Z

Could you please have a look at the failing workflows?
Please also make sure in the future to try your code once before committing.

lenaploetzke · 2026-07-21T11:07:02Z

+#include <mesh_handle/mesh_io.hxx>              /** Used to export mesh to vtk files. */
+#include <mesh_handle/concepts.hxx>
+#include <t8_types/t8_vec.hxx>          /** t8 vector dataclass. */
+#include "t8_mesh_tutorials_common.hxx" /** Default adaption function. */


Suggested change

#include "t8_mesh_tutorials_common.hxx" /** Default adaption function. */

#include "t8_mesh_tutorials_common.hxx" /** Adaption function definition used for this tutorial. */

lenaploetzke · 2026-07-21T11:19:52Z

+#include <t8_types/t8_vec.hxx>          /** t8 vector dataclass. */
+#include "t8_mesh_tutorials_common.hxx" /** Default adaption function. */
+#include <memory>
+#include <span>


Suggested change

#include <span>

Not used anymore

lenaploetzke · 2026-07-21T11:20:04Z

+#include <mesh_handle/constructor_wrappers.hxx> /** Wrapper for basic Cmesh to mesh_handle conversions. */
+#include <mesh_handle/mesh_io.hxx>              /** Used to export mesh to vtk files. */
+#include <mesh_handle/concepts.hxx>
+#include <t8_types/t8_vec.hxx>          /** t8 vector dataclass. */


Suggested change

#include <t8_types/t8_vec.hxx> /** t8 vector dataclass. */

unused

lenaploetzke · 2026-07-21T11:24:59Z

+  /* Generate a hybrid hypercube, made out of cubes, prisms etc. */
+  auto mesh = t8_mesh_handle::handle_hypercube_hybrid_uniform_default<TMeshClass> (level, comm);
+  /* Defining the adaption parameters. */
+  struct adapt_data adapt_params = { { 0.5, 0.5, 1.0 }, 0.2, 0.4 };


Suggested change

struct adapt_data adapt_params = { { 0.5, 0.5, 1.0 }, 0.2, 0.4 };

adapt_data adapt_params = { { 0.5, 0.5, 1.0 }, 0.2, 0.4 };

I think with struct it is C code and without is modern cpp

lenaploetzke · 2026-07-21T11:26:04Z

+  mesh->set_balance ();
+  mesh->set_partition ();


Why is balance, partition and ghost here?

lenaploetzke · 2026-07-21T14:03:53Z

+
+  /* Committing the initial mesh. */
+  mesh->commit ();


You dont need to commit before doing something

lenaploetzke · 2026-07-21T14:04:57Z

+  /* Creating the adapted mesh as a copy of the initial mesh (Initial mesh can't be refined because it is already committed.) */
+  auto mesh_adapt = std::make_unique<mesh_type> (*mesh);
+


I think it would be good to have seperate functions for this just as in step 3.

lenaploetzke · 2026-07-21T14:06:32Z

+  /* Partitioning the mesh.*/
+  mesh_partition_balance->set_partition ();


Balance makes no sense after adapting only once. You will need 2 times adaption for this to see a result. ( or recursive but this si not possible for the mesh handle at the moment)

Schmitt added 5 commits June 19, 2026 09:37

First Changes and File Creation

05c741b

Spellchecking correct

53199cb

Mesh_handle_tutorial Step3

665d24c

Mesh_handle_tutorial Step3

9523fc5

Mesh_handle_tutorial Step3 fixed and Step4 added.

604e003

Vyp3er changed the title ~~Mesh handle tutorials~~ Improvement: Mesh handle tutorials Jul 1, 2026

added bsd license

282f592

Vyp3er marked this pull request as ready for review July 1, 2026 08:46

Merge remote-tracking branch 'origin/main' into mesh_handle_tutorials

9f7696b

lenaploetzke self-requested a review July 1, 2026 08:52

lenaploetzke self-assigned this Jul 1, 2026

spell checking corrected

bd84430

lenaploetzke reviewed Jul 16, 2026

View reviewed changes

Vyp3er and others added 5 commits July 17, 2026 09:45

Merge branch 'main' into mesh_handle_tutorials

ff4aa99

Apply suggestion from @lenaploetzke

d0dc470

Co-authored-by: lenaploetzke <70579874+lenaploetzke@users.noreply.github.com>

Documentation Changes and Renaming

ca472bd

added documentation and comments

9896011

Added Scope into main to prevent deletion Error

a05095c

lenaploetzke reviewed Jul 20, 2026

View reviewed changes

Integrated Review and cleaned up the comments.

bfe57f8

lenaploetzke reviewed Jul 20, 2026

View reviewed changes

Schmitt added 2 commits July 20, 2026 16:40

Adapted to comments.

b79b1d6

renamed element data tutorial to step 5

7b316f3

lenaploetzke reviewed Jul 21, 2026

View reviewed changes

	* Therefor, this is the same as general/t8_step5_element_data.cxx but using the mesh handle interface instead of the forest
	* Therefore, this is the same as general/t8_step5_element_data.cxx but using the mesh handle interface instead of the forest

	* This is step5 of the t8code tutorials.
	* This is step5 of the mesh handle tutorials.

	#include <mesh_handle/concepts.hxx>
	#include <mesh_handle/concepts.hxx>/** Include this to use c++ concepts related to the mesh handle. This can be used to constraint the template parameters to only allow mesh handle classes. */

	#include "t8_mesh_tutorials_common.hxx" /** Default adaption function. */
	#include "t8_mesh_tutorials_common.hxx" /** Adaption function definition used for this tutorial. */

	struct adapt_data adapt_params = { { 0.5, 0.5, 1.0 }, 0.2, 0.4 };
	adapt_data adapt_params = { { 0.5, 0.5, 1.0 }, 0.2, 0.4 };

		/* Creating the adapted mesh as a copy of the initial mesh (Initial mesh can't be refined because it is already committed.) */
		auto mesh_adapt = std::make_unique<mesh_type> (*mesh);

		/* Partitioning the mesh.*/
		mesh_partition_balance->set_partition ();

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lenaploetzke commented Jul 21, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Vyp3er commented Jun 22, 2026 •

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