Returns a bool indicated whether the mesh is read/write enabled.
The bool indicates whether the mesh is read/write enabled. This value can be set using the Read/Write Enabled checkbox when a model is imported, or by setting the value of
markNoLongerReadable when calling Mesh.UploadMeshData.
A dynamic Mesh created from script always returns true.
Meshes not marked readable will throw an error on accessing any data arrays from script at runtime. Access is allowed in the Unity Editor outside of the game and rendering loop.