Creating node material presets for custom node space

Deyan

Hi, is it possible to define custom node material presets for a custom node space?

It seems that the node material presets are empty for the "Example" node space, and I couldn't find anything related to adding such presets in the SDK (or the examples).
If there is a way - is it also possible to instantiate such a preset with a command plugin?

Manuel

Hi,

I've asked the dev about how to do that and to clarify some points about that. I'll be right back once I got more information.

Cheers,
Manuel

Manuel

Hi,

I've got some informations. It's not possible to insert your own material presets in that menu.

Cheers,
Manuel.

Deyan

OK, thanks for the answer.

About my second question - what is the proper way of creating a node material instance and modifying its graph to a "preset". I want to define several such presets as commands.
There is no example for this and there seems to be no direct function for getting a mutable graph instance. From browsing the interface of NodeMaterial it seems the steps for achieving this are:

Create a NodeMaterial instance.
Add the desired node space to the material.
Get the immutable version of the graph for the node space with NodeMaterial::GetGraph(..).
Get the mutable node system from the immutable graph with NodesGraphModelInterface::GetMutableNodeSystem(..)
Do modifications.

Is my assumption correct and is this the expected way of achieving this?

Manuel

Hi,

you can create those preset with a commandData sure.

When you add the graph to your node material it will call the function you defined in maxon::nodes::NODESPACE::CREATEMATERIALGRAPHFUNC See Proving Default Graph Setup for more information. So be sure to remove the nodes added by this function if they are not needed.

You must create a NodeMaterial, insert it in the document, add the graph for the right nodespace and retrieve the graph itself (by first retrieving the nimbusref). We got an example on this page: Reading and Modifying Node
This page also contains an introduction to Transaction. maxon::GraphModelInterface::BeginTransaction must be used if you want to modify the graph. You can than Commit your changes, which will ensure the graph is in a correct state. You can have a look a nodespace_impl.cpp, you will find the function CreateMaterialGraphDefaultSetup. remarque: this function doesn't need transactions to modify the graph.
In this handbook, we are using transaction to modify some port's value inside a graph. With both examples, you will understand how to add nodes, connect them, and sets values.

Cheers,
Manuel.