Problem with I SIMPA'S SPPS calculation

[anabragad]

I imported a model, remeshed it, and set up sources/receivers, then ran calculation SPPS. I followed the guidelines provided in the under Tutorials. The console reads as follows:

17:44:19: Scene repair complete
17:44:19: Meshing with the following parameters:
tetgen.exe -pq2 -A -n "C:\Users\Ana Paula\AppData\Roaming\isimpa\current\instance1\temp\scene_mesh.poly"
17:44:19: External code execution
17:44:19: meshing\tetgen\tetgen.exe -pq2 -A -n "C:\Users\Ana Paula\AppData\Roaming\isimpa\current\instance1\temp\scene_mesh.poly"
17:44:19: tetgen.exe : Opening C:\Users\Ana Paula\AppData\Roaming\isimpa\current\instance1\temp\scene_mesh.poly.
tetgen.exe : Opening C:\Users\Ana Paula\AppData\Roaming\isimpa\current\instance1\temp\scene_mesh.var.
tetgen.exe : Delaunizing vertices...
tetgen.exe : Delaunay seconds: 0.002
tetgen.exe : Creating surface mesh ...
tetgen.exe : Surface mesh seconds: 0.001
tetgen.exe : Constrained Delaunay...
tetgen.exe : A self-intersection was detected. Program stopped.
tetgen.exe : Hint: use -d option to detect all self-intersections.

17:44:19: Meshing complete
17:44:19: Loading mesh ASCII file...
17:44:19: Loading ASCII files from mesh generator complete
17:44:19: Total time of meshing: 3454 ms
17:44:28: External code execution
17:44:28: core\spps\spps.exe "C:\Users\Ana Paula\AppData\Roaming\isimpa\current\instance1\report\SPPS\2022-12-09_17h44m16s\config.xml"
17:44:29: spps.exe :SPPS version 2.2.1
spps.exe :C:\Users\Ana Paula\AppData\Roaming\isimpa\current\instance1\report\SPPS\2022-12-09_17h44m16s\tetramesh.mbin
spps.exe :Tetrahedron file is empty, the calculation can't be done !
spps.exe :Unable to read the tetrahedalization of the scene mesh file, calculation canceled.

17:44:29: Calculation time: 189 ms
17:44:29: Copy of calculation parameters
17:44:44: Refreshing Tab 'Results'
17:44:44: Total time calculation: 28306 ms

Anyone knows what i can do? I need this with urgency :(

[nicolas-f]

Hi, can you share your 3d model please ?

Thx

[daveinman]

I believe have the same problem. I export a model (.ply file) from FreeCAD, import a new scene, then get the same type of error during either a Classical or SPPS run. The model is of a room with a coved ceiling, but the whole room is surrounded by a shell to provide a watertight space since doors have gaps under them. Here's the output of two SPPS calculations with the first being in debug mode:

13:36:54: Warning: Debug mode mesh, nothing will be done
13:36:54: Meshing with the following parameters:
tetgen.exe -d "C:\Users\davei\AppData\Roaming\isimpa\current\instance1\temp\scene_mesh.poly"
13:36:54: External code execution
13:36:54: meshing\tetgen\tetgen.exe -d "C:\Users\davei\AppData\Roaming\isimpa\current\instance1\temp\scene_mesh.poly"
13:36:55: tetgen.exe : Opening C:\Users\davei\AppData\Roaming\isimpa\current\instance1\temp\scene_mesh.poly.
tetgen.exe : Delaunizing vertices...
tetgen.exe : Delaunay seconds:  0.026
tetgen.exe : Creating surface mesh ...
tetgen.exe : Surface mesh seconds:  0.018
tetgen.exe : Detecting self-intersecting facets...
tetgen.exe : 
tetgen.exe : No faces are intersecting.
tetgen.exe : 
tetgen.exe : Self-intersection seconds:  0.085

13:36:55: Meshing complete
13:36:55: Total time of meshing: 858 ms
13:36:56: External code execution
13:36:56: core\spps\spps.exe "C:\Users\davei\AppData\Roaming\isimpa\current\instance1\report\SPPS\2025-07-24_13h36m54s\config.xml"
13:36:56: spps.exe :SPPS version 2.2.1

13:36:56: spps.exe :C:\Users\davei\AppData\Roaming\isimpa\current\instance1\report\SPPS\2025-07-24_13h36m54s\tetramesh.mbin
spps.exe :Tetrahedron file is empty, the calculation can't be done !
spps.exe :Unable to read the tetrahedalization of the scene mesh file, calculation canceled.

13:36:56: Calculation time: 269 ms
13:36:56: Copy of calculation parameters
13:36:56: Refreshing Tab 'Results'
13:36:56: Total time calculation: 2060 ms
13:37:53: External code execution
13:37:53: meshing\tetgen\preprocess C:\Users\davei\AppData\Roaming\isimpa\current\instance1\temp\scene_mesh.poly
13:37:53: preprocess - The mesh file cant be found !

13:37:53: Scene repair complete
13:37:53: Meshing with the following parameters:
tetgen.exe -pq5 -A -n -Y "C:\Users\davei\AppData\Roaming\isimpa\current\instance1\temp\scene_mesh.poly"
13:37:53: External code execution
13:37:53: meshing\tetgen\tetgen.exe -pq5 -A -n -Y "C:\Users\davei\AppData\Roaming\isimpa\current\instance1\temp\scene_mesh.poly"
13:37:55: Program execution failed
13:37:55: Total time of meshing: 2482 ms
13:37:55: Error:Meshing aborted: please, see console messages for more information 
13:37:56: External code execution
13:37:56: core\spps\spps.exe "C:\Users\davei\AppData\Roaming\isimpa\current\instance1\report\SPPS\2025-07-24_13h37m53s\config.xml"
13:37:56: spps.exe :SPPS version 2.2.1
spps.exe :C:\Users\davei\AppData\Roaming\isimpa\current\instance1\report\SPPS\2025-07-24_13h37m53s\tetramesh.mbin
spps.exe :Tetrahedron file is empty, the calculation can't be done !
spps.exe :Unable to read the tetrahedalization of the scene mesh file, calculation canceled.

13:37:56: Calculation time: 214 ms
13:37:56: Copy of calculation parameters
13:37:56: Refreshing Tab 'Results'
13:37:56: Total time calculation: 3617 ms

Attached is a zip of the .ply file in use.

isimpa_github_data.zip

Though I have fused the room and surrounding shell "Parts" in FreeCAD into a one Fused object, I am asked to select from more than one volume during the import scene steps. One selection seems to bring in the shell and another brings in the room with its coved ceiling. I don't seem able to get them both to come into the program.

[nicolas-f]

Though I have fused the room and surrounding shell "Parts" in FreeCAD into a one Fused object, I am asked to select from more than one volume during the import scene steps. One selection seems to bring in the shell and another brings in the room with its coved ceiling. I don't seem able to get them both to come into the program.

Hi,

I see you have run your original model into a “Average model remesh”. But your model is quite simple so this is not required.

FreeCad and Blender can repair STL 3d models. You can run the mesh tool of FreeCad on your original model (not the one you provided here) and export the result to I-Simpa

[daveinman]

Thank you Nicolas. I have been trying this technique but without any luck yet. I’m inexperienced so I expect some troubles. I appreciate you taking the time to respond. Dave David M. Inman 9301 NE 83rd Ave. Vancouver, WA 98662 Phone: (503) 764-7200 ***@***.***

…

On Jul 24, 2025, at 11:16 PM, nicolas-f ***@***.***> wrote: nicolas-f left a comment (Universite-Gustave-Eiffel/I-Simpa#348) <#348 (comment)> Though I have fused the room and surrounding shell "Parts" in FreeCAD into a one Fused object, I am asked to select from more than one volume during the import scene steps. One selection seems to bring in the shell and another brings in the room with its coved ceiling. I don't seem able to get them both to come into the program. Hi, I see you have run your original model into a “Average model remesh”. But your model is quite simple so this is not required. FreeCad and Blender can repair STL 3d models. You can run the mesh tool of FreeCad on your original model (not the one you provided here) and export the result to I-Simpa — Reply to this email directly, view it on GitHub <#348 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAF7PYPOSOFOHBNFQQO4SUD3KHDTHAVCNFSM6AAAAACCJ5ZPS2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTCMJWGU2DCNBVGY>. You are receiving this because you commented.