edit: I briefly checked with scripts/05_modules/node/create_redshift_nodematerial_2024.py and there, with Redshift, it works and the assets show up in the inspector right away. Which hints at this being an exlusive VRay issue which only can be solved by Chaos.

c4d.MSG_UPDATE does not seem to work.
If I manually link the textures, they are correctly detected and displayed in the Project Asset Inspector. However, when importing them via Python, they are not detected.
Redshift and Arnold do not have this issue.
I hope you can help me figure out what might be wrong. Here is my code:

import c4d
import maxon

doc: c4d.documents.BaseDocument 


def main() -> None:
    c4d.CallCommand(1058751) # V-Ray Node Material

    mat = doc.GetFirstMaterial()

    urlTexRust = r"D:\RustPaint0291_M.jpg"  # image path
    
    idTextureNode: maxon.Id = maxon.Id("com.chaos.vray_node.texbitmap")
    brdfMaterial: maxon.Id = maxon.Id("com.chaos.vray_node.brdfvraymtl")

    nodespaceId = c4d.GetActiveNodeSpaceId()
    nimbusRef = mat.GetNimbusRef(nodespaceId)
    if not nimbusRef:
        return
    
    graph = nimbusRef.GetGraph()
    if not graph:
        raise RuntimeError("Could not add graph to material.")
        return

    result: list[maxon.GraphNode] = []
    maxon.GraphModelHelper.FindNodesByAssetId(graph, brdfMaterial, True, result)
    if len(result) < 1:
        raise RuntimeError("Could not find Mat node in material.")
    matNode: maxon.GraphNode = result[0]
        
    with graph.BeginTransaction() as transaction:

        rustTexNode: maxon.GraphNode = graph.AddChild(maxon.Id(), idTextureNode)
        pathRustPort: maxon.GraphNode = rustTexNode.GetInputs().FindChild(
        "com.chaos.vray_node.texbitmap.file")

        pathRustPort.SetPortValue(urlTexRust)

        rustTexColorOutPort: maxon.GraphNode = rustTexNode.GetOutputs().FindChild(
        "com.chaos.vray_node.texbitmap.output.default")

        brdfBaseColorInPort: maxon.GraphNode = matNode.GetInputs().FindChild(
        "com.chaos.vray_node.brdfvraymtl.diffuse")
        
        rustTexColorOutPort.Connect(brdfBaseColorInPort, modes=maxon.WIRE_MODE.NORMAL, reverse=False)
        

        transaction.Commit()

    c4d.EventAdd()
    
if __name__ == "__main__":
    main()

Thank you for reaching out to us. Assets in the sense of the Asset Inspector are realized via MSG_GETALLASSETS in general. For material nodes you have to set IMAGENODEASSETID and IMAGENODEPORTS on the node space, or directly implement MATERIALMESSAGEHANDLERFUNC (all attributes are in the same namespace). Under the hood, all these Nodes API systems pipe back into MSG_GETALLASSETS and it is the implementer who must realize them, i.e., Chaos in this case. You as a user cannot do anything about, the asset data is either there or not.

I am currently on my Mac where I do not have VRay installed. The main question would be: Does VRay show its assets when you wire up the same materials manually? I think it does, right? You can try sending a MSG_UPDATE to the material holding the graph(s) but that should not be necessary by default(myMaterial.Message(c4d.MSG_UPDATE)). It could be that VRay is doing some black magic with its assets and MATERIALMESSAGEHANDLERFUNC which is not correctly setup when you programmatically create graphs. But that (a) strikes me as a bit unlikely and (b) only Chaos can help you with that.

VRay is as a third party plugin generally out of scope of support, so their support is your best shot. But when you share your code and a scene, I can have an informal look as what is going wrong there (but it might take a week or so before I get to it).

Cheers,
Ferdinand