How to Get and Set Specific Node Attributes in Maxon Graph API?

Amazing_iKe

I've just finished reading the Graph Descriptions Manual, and I now understand how to use dictionaries to create materials. However, I’m not sure how to query a specific attribute of a node.
Do I need to first find the node's ID?

In Maya's API, I can do something like this:```
code_text

texture_path = cmds.getAttr(file_node + ".fileTextureName")

But in the Maxon API, I don’t know how to get or set a specific property of a node.
Could you help me understand how to read or modify specific attributes (e.g., texture path or scale) in an existing graph node?

Dunhou

Hey @Amazing_iKe，

As I know Graph Description used to modify graphs but have no methods to get port values.

You should use maxon.GraphNode, like GetPortValue(), or just use GetValue(''value).

Cheers~
DunHou

ferdinand

Hello @Amazing_iKe,

Welcome to the Maxon developers forum and its community, it is great to have you with us!

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About your First Question

@Dunhou is right, this, querying for values is not possible with graph descriptions at the moment (querying for nodes is possible to some extent) . What you could do, is use a graph query to select some node over its properties, and then just write its ID. ApplyDescription returns the true nodes of a graph sorted over their IDs. Then you could grab that node you are interested in, get the port you want, and write the value based on the existing value. Or you could let graph descriptions be graph descriptions and just use the low level API directly. You can have a look at the Nodes API examples for some inspiration how this lower level API works.

On of the things I am working on at the moment, is extending the query ability of graph descriptions. What I have implemented so far, is nested queries (you can select nodes over them being connected in a specific way), more query operators (<, >, !=, regex, etc.), and something I dubbed query compositions that allows you to query one node property for more than one value, so that can do stuff like checking if something is smaller than 1, AND bigger than 0, AND not exactly 0.5, or that something matches the regex "$foo." OR "$bar.". What has been also added so far, is a new function called EvaluateQuery which allows you to run queries without having to apply a description. But this function also operates on the level that it will return nodes, and not ports or even values.

I of course also have thought about this, querying for values directly, but I have not implemented it for now, as you can do it somewhat easily yourself with EvaluateQuery (and to some extent even with ApplyDescription) by just getting the port and then its value. But I understand the alure, maybe when I have time, I will fit in a EvaluateValueQuery. The update was planned for one of later 2025.X releases, but at the moment it looks more like that it will be 2026.0.0.

When you need help with the lower level Nodes API, just open a posting here on the forum with what you got.

Cheers,
Ferdinand