I think what i want to do is quite easy, but i’m still stuck…
I want (with gdscript) to load a mesh in my scene (actually an obj, but i Can change this to gltf if it’s help) and add per vertex data (xyz velocity) load from a txt file.
My data (obj and txt) have been generated with paraview, so vertex information are in the same order in both files.
I easily make the fonction to read my txt file and i have been able to load my obj and add it to my 3dmeshinstance.
But i cannot find the way to add an array_custom to my mesh to use per vertex data intro my shader.
Actually i have a plane.mesh = imported_obj and customvel in PackedFloat32Array() with all the values already filled