ID 274272 - Parameter UI is not correctly populated for LookFileManager override nodes that rely on incoming scene data

Problem summary:

When adding an override to the LookFileManager SuperTool, such as a Material node in edit mode (or any that rely on incoming scene data), the parameter UI for the override node is not correctly populated.  This is because the internal Unfork3D node fails to provide an Op chain when the node graph is evaluated at a point above a corresponding Fork3D node.

Steps to reproduce:

1. Create a LookFileManager node and add a Material node override.
2. Set this node  to 'edit' mode, and edit an existing material.

Expected behaviour:

The incoming material parameter interface is populated.

Actual behaviour:

The material parameter interface is blank.

More direct reproduction steps:

View the scene graph at the internal '__PostOverrides' node of a LookFileManager node.  Note the scene graph is in error.

Workaround:

No known workaround.

Reproduced versions/platforms:

• 2.5v5

Customer version/platform:

2.5v5 Linux