MATX-303 : Material Node discovery

[kwokcb]

Discover Logic.

• discovery returns any node or nodegraph which has a one or more material outputs
• Works on a nodegraph, materialassign, or document as the element to test from.
• Document level . It ignores implementation nodegraphs.
• Nodegraph discovery does not check if the graph is an implementation or not.

Configurations Supported.

Refer to images in: https://github.com/materialx/MaterialX/issues/737 for graphical view of configurations tested.

Test Results.

Material nodes discovered which are referenced by materialassigns

• Found material node: top_level_material_assigned
• Found material node: top_level_material_in_graph_assigned/surfacematerial1
• Found material node: top_level_material_def_assigned

Material nodes discover which are within a nodegraph

• Found output material node: top_level_material_in_graph_no_assign/surfacematerial1
• Found output material node on definition: NG_material_def_material_1_0/surfacematerial1
• Found output material node: top_level_material_in_graph_assigned/surfacematerial1

Material nodes or nodegraphs discovered within a Document This scans at the document level first, and then for each nodegraph scans inside. The difference when scanning at document level is that nodegraph implementations are skipped so NG_material_def_material_1_0/surfacematerial1 is not return.

• NodeGraph Node: top_level_material_in_graph_no_assign/surfacematerial1
• NodeGraph Node: top_level_material_in_graph_assigned/surfacematerial1
• Node: top_level_material_no_asssign
• Node: top_level_material_assigned
• Node: top_level_material_def
• Node: top_level_material_def_assigned