String values for the "FindChild"?

Manuel

Hi,

we included in the c++ documentation information about how to find those IDs. The show IDs command was moved to the preferences (Node editor) and replaced by a checkbox. From there, you will be able to find the symbol corresponding to the Id of the port. For Redshift, those symbols are not exposed so you need to use the value of the ID.

You also have the resource editor to understand how the descriptions is built. Launch the resource editor using the commander. If you click the first arrow on the top left, you can start typing the ID of the node, like "fresnel". The list size will shrink to only display the database where there is an element with "fresnel" on its name.

Once the node is selected, you will be able to select the port on the tree and see the Identifier field on the right in the General tab.

Redshift uses a full reverse domain name notation to identify its ports, so the Id of the port is com.redshift3d.redshift4c4d.nodes.core.fresnel.fresnel_useior

Some port can be port bundle, you can see it from its datatype. Below you can see the redshift texture node. To define the value of the filename you need to know the bundle port's ID

The ports ID is com.redshift3d.redshift4c4d.nodes.core.texturesampler.tex0. As it is a port bundle, you need to check the subid. Search for com.redshift3d.redshift4c4d.portbundle.file in the database.

You will find that the port has the ID path.
hope that helped.

Cheers,
Manuel

bentraje

@Manuel

Thanks for the response. And yes, your answer does present the ID of the Path (or the ID of the Port?) which I guess the one needed for the connect method (Well my recent threads is just really to have connect ports of two nodes together because I can't find a decent example)

Anyhow, what I'm really after is the
String values for the "FindChild"?

The reason why I prefer it over the com.redshift3d.redshift4c4d.nodes.core.fresnel.fresnel_useior is because that one is so verbose.
I just want to use FindChild(fresnel_useior). Much clearer to read.

Is this still possible? I tried checking the Resource Editor for some clues.
I tried

FindChild(perp_color)
FindChild(Perpendicular Color`)

Am I looking at the wrong areas?

Manuel

There is no string they are just IDs. The string is converted to an maxon::Id

You can not use fresnel_useior because this is not the ID of the port. The ID of the port is com.redshift3d.redshift4c4d.nodes.core.fresnel.fresnel_useior (and yes this is a bit verbose)

The symbol for this ID (at least in c++) should be redshift3d::redshift4c4d::nodes::core::fresnel::fresnel_useior but again they are not exposed.

@ferdinand created a nice c++ example about connecting ports in redshift and using the texture node. You can see there that he first search for the port bundle and then, search for the file port.

    // Retrieve the "Filename" port of the texture node.
    maxon::GraphNode tex0InportRust = rustTextureNode.GetInputs().FindChild(
      maxon::Id("com.redshift3d.redshift4c4d.nodes.core.texturesampler.tex0")) iferr_return;
    if (!tex0InportRust.IsValid())
      return maxon::UnexpectedError(MAXON_SOURCE_LOCATION, "Failed to access port."_s);
 
    // The "Filename" port is a port bundle which consists out of two sub-ports, the "path" and the
    // "layer" port. The texture URL is written into the "path" sub-port.
    maxon::GraphNode pathInportRust = tex0InportRust.FindChild(maxon::Id("path")) iferr_return;
    if (!pathInportRust.IsValid())
      return maxon::UnexpectedError(MAXON_SOURCE_LOCATION, "Failed to access port."_s);
 
    // Set the path of the rust texture node to the URL of the rust texture asset.
    pathInportRust.SetDefaultValue(rustTextureUrl) iferr_return;

Cheers,
Manuel

bentraje

@Manuel

RE: There is no string they are just IDs.
Ah. I guess I was misguided.
I was thinking the FindChild spits out the verbose id.
For the sake of argument, why did the modify_port_value.py script used a string value?
colordePort = bsdfNodeInputs.FindChild("color")
That's the basis of my confusion lol

RE: nice c++ example
Missed this one out. Thanks! At least now I have a base example to check.

Manuel

@bentraje said in String values for the "FindChild"?:

For the sake of argument, why did the modify_port_value.py script used a string value?

When I wrote the nodes examples, the symbols were not necessarily available, and/or public. The node API is now more stable, i need to update some examples.

Cheers,
Manuel

bentraje

@Manuel

Thanks for the response but it still gives me error though.

I tried this one:

fresnel_port = node.FindChild(maxon.Id("com.redshift3d.redshift4c4d.nodes.core.fresnel.fresnel_useior"))

It gives me an error of
TypeError: unable to convert builtins.NativePyData to @net.maxon.datatype.internedid

or is there a different way to access the port?

bentraje

I also tried the actual string id

fresnel_port = node.FindChild("com.redshift3d.redshift4c4d.nodes.core.fresnel.fresnel_useior")
it gives me null.

All of the examples in the github does not access one port (it access all ports) except for the modify_port_value_r24.py so I'm not sure how to proceed.

bentraje

Example in this thread is using a generic string too instead of an ID so can't really refer directly

https://developers.maxon.net/forum/topic/14101/how-to-show-nodes-api-nodes-in-the-node-editor/4

Manuel

Hi,

sorry, we must define which version you want to use. Depending on the version this can vary a lot. On some version, functions are in a different class, Strings are not converted to maxon::Id. Using python for the node API was a bit limited in r25.

Cheers,
Manuel

bentraje

@manuel

gotcha sorry about that.
what are my options for R25? (i.e. how can I use the FindChild with the Maxon Id ? )

Manuel

hi,

Something like this should works in R25. This will find the base_color ports of the redshift material. The Material must be a standard material and the standard node must be selected.

import c4d
import maxon
from c4d import gui
from maxon.frameworks import nodes

# Main function
def main():
    mat = doc.GetActiveMaterial()
    if mat is None:
        raise ValueError("can't retrieve the selected material")

    nodespaceId = c4d.GetActiveNodeSpaceId()
    nodemat = mat.GetNodeMaterialReference()
    graph = nodemat.GetGraph(nodespaceId)

    def PrintNode(node):
        colorNode = node.GetInputs().FindChild("com.redshift3d.redshift4c4d.nodes.core.standardmaterial.base_color")
        print (colorNode)
        return True

    graph.GetSelectedTrueNodes(PrintNode)
    # With newest version of cinema 4D,  the function to retrieve the selected nodes was moved to another class so instead use the new one.
    #maxon.GraphModelHelper.GetSelectedNodes(graph, maxon.NODE_KIND.ALL_MASK, PrintNode)
# Execute main()

if __name__=='__main__':
    main()

Cheers,
Manuel

bentraje

@Manuel

Gotcha. Thanks for the clarification.
Sorry for the trouble.

Works as expected. Will close this thread now.