Can't access mesh data if Mesh.isReadable is false

[De-Panther]

In the regular editor(Editor scripts, windows, inspectors, etc...) we can access to mesh data(vertices, triangles, etc...) even if it's locked, while in EditorVR it'll show errors as if we are on playing mode.

The regular editor can access mesh data of locked meshes even while the EditorVR is running.

[mtschoen-unity]

Are you talking about in the EditorVR inspector, or using code that executes during edit mode while EVR is running? I'm pretty sure I know what error you're talking about, but can you paste the stacktrace (maybe in a gist?) and detailed steps to reproduce the issue?

[De-Panther]

We get an error similar to this: "Not allowed to access vertices on mesh 'mesh_name' (isReadable is false; Read/Write must be enabled in import settings)" or this "Not allowed to access triangles/indices on mesh 'mesh_name' (isReadable is false; Read/Write must be enabled in import settings)"

It happens when we try to access locked mesh from a tool or workspace in EVR. If we try to access the same mesh from Editor(CustomEditor) or EditorWindow class, it works, and it works even if someone use EVR while we try to access from EditorWindow.

Steps to reproduce: Import a model and disable Read/Write. Add the model to a scene. Attach the TestMesh component from the attached package EVR_Mesh_Access.zip Assign the MeshFilter to the component. You'll get "Not allowed to access" error and then 0 as the count for mesh.triangles.Length. Then right click on the model's GameObject name in the Hierarchy window and select Test Mesh. You'll get the correct count for mesh.triangles.Length.

TestMesh component has the ExecuteInEditMode attribute, so it works similar to the way tools and workspaces in EVR works.