Question How to manipulate a shader graph enum using C#?

I have a component whose function is to control various artistic expressions of a material, but is not itself an object with that material.

What I want is an enum with various blending modes as a dropdown list, but I'm not sure how to make the code communicate with shader graph in the same way you can with global properties.

So firstly, this is what I want: a dropdown list that represents the Enum property from the shader graph:


Except not exposed on the material itself, but on a separate controller object in the scene.

This is easy with floats, integers, vectors, colors, etc., as they all have predefined Shader.SetGlobal____ properties that can be called as long as you have a node with the corresponding reference ID.

Enum, on the other hand, apparently cannot be converted to a float or an integer. An Enum's list has corresponding integer values, though, so this is counterintuitive to me.

This is the code I have right now. It creates the dropdown (like in the image above) but even though I've given it the correct Reference ID _EDGEGLOWBLENDINGMODE, it doesn't seem to communicate at all with that shader graph node. I've trimmed out the unrelated portions:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. [ExecuteInEditMode]
6.  
7. public class Interactor : MonoBehaviour
8. {  
9.  
10.     [SerializeField]
11.  
12.     [Header("Edge Blending")]
13.  
14.     public Material edgeGlowMaterial;
15.     public enum BlendingMode
16.     {
17.         Multiply,
18.         Add,
19.         SubA,
20.         SubB
21.     }
22.    
23.     public BlendingMode blendingMode;
24.    
25.  
26.     private void Start()
27.     {
28.         int blendingModeIndex = (int)blendingMode;
29.         edgeGlowMaterial.SetInt("_EDGEGLOWBLENDINGMODE", blendingModeIndex);
30.     }
31.     // Update is called once per frame
32.     void Update()
33.     {
34.        
35.     }
36. }

I think I know why this is not working: the sort of tutorial I followed just trying to get the dropdown to appear is requiring the definition of a material at line 14; the SetInt command on line 29 is trying to set the properties of that material, which is really just irrelevant here.

But yeah, I don't know what I would need to do to connect the dropdown to the actual enum node in the shader graph. I don't know if my logic is just backwards, or if this is even possible at all..

 

But this is enum keyword, it's keyword, so setting Int not gonna work, unless there is some hidden functionality I do not know. If you want to set material keyword there is material.SetKeyword, or Shader.SetKeyword to set global keyword.

https://docs.unity3d.com/Packages/com.unity.shadergraph@12.0/manual/Keywords.html

 

Like you said, I don't think there is a way to use Int, so I'm trying to find out how I can connect my drop down list to the enum keyword via the script..

Your link to the documentation looks promising, but it's not terribly descriptive, and seems to assume a level that's yet way over my head..