Soft body does nothing if it's Mesh is array mesh programmatically created with SurfaceTool

[rasikrodri]

Tested versions

A soft body with a procedurally generated mesh does not do anything. When you run the game the mesh just appears at coordinates 0,0,0,

System information

Windows 10 - Godot 4.2.2 stable

Issue description

E 0:00:00:0471 create_from_trimesh: Condition "p_indices.is_empty()" is true. Returning: false
<C++ Source> servers/physics_3d/godot_soft_body_3d.cpp:469 @ create_from_trimesh()

Steps to reproduce

-Just run the scene and you will see that the volleyball net is static at 0,0,0 coordinates, that's it. Also there is an error in the console:

Minimal reproduction project (MRP)

ProceduralSoftBodyBug.zip

[clayjohn]

The error leads me to think that the mesh needs to have indices. Can you try adding indices to the mesh when you create it? You can do that using surface_tool.index() before committing the mesh to an ArrayMesh

[rasikrodri]

You are correct. That fixed the problem, now it works

…

On Tue, May 7, 2024 at 10:49 PM Clay John ***@***.***> wrote: The error leads me to think that the mesh needs to have indices. Can you try adding indices to the mesh when you create it? You can do that using surface_tool.index() before committing the mesh to an ArrayMesh — Reply to this email directly, view it on GitHub <#91690 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACO7IMA4II66IVXSEWTAOD3ZBGHEZAVCNFSM6AAAAABHMAFUFGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDAOJZGYZTGMRSGM> . You are receiving this because you authored the thread.Message ID: ***@***.***>

-- *Rasik Rodriguez Garcia* *Software Developer* *"Today is a Better Day"* *Mobile:(336) 564-5817* ***@***.*** ***@***.***>*

[clayjohn]

Thanks for checking!

We should add a clear error message to the set_mesh() function so it can error out early and give users useful feedback. The error can be added here:

godot/servers/physics_3d/godot_soft_body_3d.cpp

Lines 140 to 143 in cff016d

	Array arrays = RenderingServer::get_singleton()->mesh_surface_get_arrays(soft_mesh, 0);
	ERR_FAIL_COND(arrays.is_empty());
	bool success = create_from_trimesh(arrays[RenderingServer::ARRAY_INDEX], arrays[RenderingServer::ARRAY_VERTEX]);

[rrodriguez-medicaljustice]

Thank you again!