Allow mesh data to be reuploaded without having to recreate the mesh.

Splits mjrfMeshData into config+data parts.

PiperOrigin-RevId: 952042545
Change-Id: I19a572a0f591fa0d33bbc2c32b974efc075310f4

python/mujoco/introspect/structs.py

@@ -11332,13 +11332,6 @@ STRUCTS: Mapping[str, StructDecl] = dict([
          name='mjrVertexAttribute',
          declname='struct mjrVertexAttribute_',
          fields=(
-             StructFieldDecl(
-                 name='bytes',
-                 type=PointerType(
-                     inner_type=ValueType(name='void', is_const=True),
-                 ),
-                 doc='vertex data',
-             ),
              StructFieldDecl(
                  name='usage',
                  type=ValueType(name='int'),

python/mujoco/structs.cc

@@ -1078,7 +1078,7 @@ This is useful for example when the MJB is not available as a file on disk.)"));
   py::class_<raw::MjrVertexAttribute> mjrVertexAttribute(m,
                                                          "MjrVertexAttribute");
   mjrVertexAttribute.def(py::init([](int usage, int type) {
-                           return raw::MjrVertexAttribute{nullptr, usage, type};
+                           return raw::MjrVertexAttribute{usage, type};
                          }),
                          py::arg("usage") = 0, py::arg("type") = 0);
   mjrVertexAttribute.def("__copy__", [](const raw::MjrVertexAttribute& other) {