Tweak Shaders of Imported StandIn?

[dhanad]

I have a grass.ma scene, where I assigned the grass geometry its material and texture. I export the geo as a StandIn for use in another scene.

Is there any way I can manipulate/tweak the aiStandard Surface that was assigned to the geometry which is imported as StandIn? Or do I have to go back to the geo scene (i.e. grass.ma) and tweak the material there and re-export as StandIn with the tweaked look?

There must be a way to lookdev any imported StandIns no?

[dhanad]

Okay, so this is what I found out, if there is a better workflow please let me know

1. Select StandIn, then go to its shape node.
2. Under the file contents roll-out, I selected the grass shape
3. Clicked Add Assignment > Shader. This unlocks a slot where I can drag in a shader.
4. Middle-click and drag the desired material from Hypershade onto the "Shader" slot. Done.

Now I have to figure out how to modify pre-made material that was exported with the StandIn.

[teddude75 · Accepted solution]

In your scene with the grass before you make a stand in apply a ai standard surface shader. Name it something like ai_grass_shader. Now create the stand in and export the shader. In your new scene import both the shader and the stand in (no name spaces). This will allow you to change the shader properties on the stand in. Also because it's name specific you can make a shader named "ai_grass_shader" and it will render with that shader.

[dhanad]

Thanks Edward! It’s great to know using the same name will also work. Will try that method out as well!

[lee_griggs]

This is where operators strength lie. Tutorials here.

[dhanad]

Thanks Lee, I was checking out the operators. Definitely adding this to my pipeline. The tutorial is straight-forward. Thanks for the headsup!

[dany2.robert]

hello,

Is it possible to add assignments/ Operators when importing the .ass houdini? I can see the "set parameter" node in the out, but I can't see the .ass hierarchy like in maya..

[Stephen.Blair]

Yes, you can do the same things as in Maya. But there's no file browser, so you have to know the names of the Arnold nodes in the ass file.

[dany2.robert]

Thank you for your answer Stephen! I'm new to Arnold and still going through the documentation, but that seems tricky to use; how do people tweak scenes created by different artists and/or in different packages? is there a way to query the ass file?

[Stephen.Blair]

Hi @Dadin Dan

You can view an ASS file in a text editor. Look for the name parameters:

polymesh
{
 name /pPlane1/pPlaneShape1
 ...
 declare dcc_name constant STRING
 dcc_name "pPlaneShape1"
}

Or you can use selections like *.(@node=='polymesh') to see what nodes are selected. If you set the Arnold log verbosity to Debug, the names of the matched nodes are printed in the Arnold log.

Or you can use the UI in Maya to explore. And then export an ass file to see what selection strings are used by the operators.

[dany2.robert]

thanks, that's helpful !

[toby.gainesQTXCX]

Old link goes nowhere - searching through Operator tutorials also leads to dead links. However, none of the categories look like they will explain how to access a shader network that's already inside the .ass file.