Question How can I expose 'Surface Type' in shader graph

Hi

The Universal Render Pipeline/Lit shader has a 'Surface Type' property for making something transparent/opaque. In shader graph, it only seems possible to set this directly on the PBR master node.

Is it possible to add this to the blackboard somehow to expose it?

 

You can set this via .SetInt("_SurfaceType", ...) without manual exposing per material. Note that you also have to set the render queue accordingly.

Transparent:
.SetInt("_SurfaceType", 1);
.SetInt("_RenderQueueType", 4);

Opaque:
.SetInt("_SurfaceType", 0);
.SetInt("_RenderQueueType", 1);

Edit: I don't remember how I figured out which are the right numbers. Maybe debugging...

 

Thank you this worked perfectly!

 

I just discovered that in my case A LOT more shader flags have to be set and that only the transparent -> opaque conversion worked with the subset of flags shared earlier.

Transparent:

Code (CSharp):

1. transparentMat.EnableKeyword("_BLENDMODE_ALPHA");
2. transparentMat.EnableKeyword("_SURFACE_TYPE_TRANSPARENT");
3. transparentMat.EnableKeyword("_ENABLE_FOG_ON_TRANSPARENT");
4. transparentMat.DisableKeyword("_BLENDMODE_ADD");
5. transparentMat.DisableKeyword("_BLENDMODE_PRE_MULTIPLY");
6.  
7. transparentMat.SetFloat("_SurfaceType", (int)SurfaceType.Transparent);
8. transparentMat.SetFloat("_RenderQueueType", 5);
9. transparentMat.SetFloat("_BlendMode", 0);
10. transparentMat.SetFloat("_AlphaCutoffEnable", 0);
11. transparentMat.SetFloat("_SrcBlend", 1f);
12. transparentMat.SetFloat("_DstBlend", 10f);
13. transparentMat.SetFloat("_AlphaSrcBlend", 1f);
14. transparentMat.SetFloat("_AlphaDstBlend", 10f);
15. transparentMat.SetFloat("_ZTestDepthEqualForOpaque", 4f);
16.  
17. transparentMat.renderQueue = (int)UnityEngine.Rendering.RenderQueue.Transparent;

Opaque:

Code (CSharp):

1. opaqueMat.SetInt("_SurfaceType"_STRING, (int)SurfaceType.Opaque);
2. opaqueMat.SetInt("_RenderQueueType", (int)1);
3. opaqueMat.SetFloat("_AlphaDstBlend", 0f);
4. opaqueMat.SetFloat("_DstBlend", 0f);
5. opaqueMat.SetFloat("_ZTestDepthEqualForOpaque", 3f);
6. opaqueMat.renderQueue = (int)UnityEngine.Rendering.RenderQueue.Geometry;

 

Code (CSharp):

1. void ViewObstructed()
2.     {
3.         RaycastHit hit;
4.         if(Physics.Raycast(transform.position, target.position - transform.position, out hit))
5.             if(hit.collider.gameObject.name != HitObj)
6.             {
7.                 Obstruction.gameObject.GetComponent<MeshRenderer>().material.SetInt("_SurfaceType", 0);
8.                 Obstruction.gameObject.GetComponent<MeshRenderer>().material.SetFloat("Vector1_2B798094", 1f);
9.             }
10.  
11.             if(hit.collider.gameObject.tag != "Player")
12.             {
13.                 Obstruction = hit.transform;
14.                 Obstruction.gameObject.GetComponent<MeshRenderer>().material.SetInt("_SurfaceType", 1);
15.                 Obstruction.gameObject.GetComponent<MeshRenderer>().material.SetFloat("Vector1_2B798094", 0.3f);
16.                 HitObj = hit.collider.gameObject.name;
17.             }
18.             else
19.             {
20.                 Obstruction.gameObject.GetComponent<MeshRenderer>().material.SetInt("_SurfaceType", 0);
21.                 Obstruction.gameObject.GetComponent<MeshRenderer>().material.SetFloat("Vector1_2B798094", 1f);
22.             }
23.         }
24.     }

Obstruction.gameObject.GetComponent<MeshRenderer>().material.SetInt("_SurfaceType", 0);
it's for Opaque surface of PBR Master.

Obstruction.gameObject.GetComponent<MeshRenderer>().material.SetInt("_SurfaceType", 1);
it's for Transparent surface of PBR Master.

but i dont know it doesnt work.. please help me..

 

ohh,, of course i also add it too..
Obstruction.gameObject.GetComponent<MeshRenderer>().material..SetInt("_RenderQueueType", 4);
Obstruction.gameObject.GetComponent<MeshRenderer>().material..SetInt("_RenderQueueType", 1);

 

Ah Excellent thanks @youngjinna97 !

 

this didn't work for me at all

 

these do get changed but they have no effect

 

I must be missing something. Sorry for my n00bness, but you're all talking about code where the Shader graph is, well, a graph tool for shaders. What am I missing? where do you implement the code you all talk about?

 

I don't when this might have changed, but I tried this in Unity 2021 and there was no such value as _SurfaceType, but if you change it to _Surface then it works.

 

I missed this at first too. He's saying instead of setting this in ShaderGraph as a variable, you don't need to do this, because ALL URP materials have these variables dynamically defined.

i.e., why would we want a variable? So we can change it in C#, right? Well, we can change it in C# without declaring a variable.

 

I made a new solution for this problem for a custom shader graph built on lit.

What I've done to solve the problem, which feels a bit more reliable to me, is just to make two shaders (one transparent, one opaque), then, when I need to toggle at runtime (or from within the materials editor) I just do `material.shader = Shader.Find("Transparent_counterpart")`

All of the prop values get transferred seamlessly, and, presumably, this will work across versions. I think it should be the recommended method, even though it creates some duplicate code/graph.