Setting main texture from code doesn't seem to work

Unity Engine
1

So i’ve done this before, and made code from what i remember : to change the main texture when creating materials programatically, it’s either mat.mainTexture or mat.SetTextue(“_MainTex”, tex);

When it didn’t work, i checked in the Unity docs to be sure (Unity - Scripting API: Material.mainTexture) and it seems to confirm what i remember is correct.

However, after i try to set the main texture, the main texture stays at null. Am i missing something? The texture resouce is loaded, as is the shader.

Edit : not sure if it’s important, but the shader is a custom shader i made using ShaderGraph. It’s relatively simple shader with a MainTex property. I tried “MainTex” as the name, as well as “_MainTex” but so far nothing works. I also tried mat.SetTexture(“MainTex”, tex) as well as mat.SetTexture(“_MainTex”, tex) for both names. Still no results.

Here’s the code. The goal is to load texture from resource name and create a material for it.

[Serializable]
public struct MaterialInfo
{
    public string Name;
    public string File;
    public string Shader;
}

 private void GenerateMaterial(MaterialInfo info)
    {
        Shader shad = Shader.Find(info.Shader);

        if (shad == null)
        {
            return;
        }

        Material mat = new Material(shad);
        mat.name = info.Name + "_mat";
    
        Texture2D tex = Resources.Load<Texture2D>(info.File);
        if (tex == null)
        {
            Debug.LogError("No texture \"" + info.File + "\" found.");
            return;
        }
        else
        {
            mat.mainTexture = tex;
        }

        GeneratedMaterials.Add(mat);

        if (Prefab != null)
        {
            GameObject go = GameObject.Instantiate(Prefab);
            MeshRenderer mr = go.GetComponent<MeshRenderer>();
            mr.material = mat;
            mr.enabled = true;
            go.name = info.Name + "_prefab";
        }
    }
2

Pretty sure you need to use the SetXYZ(“fieldName”, fieldValue) functions to set properties of a shader, like for example:

3

SetTexture should work but the name you put in the quotes needs to match the name that you used in the shader. Does the material have a default value set for that field?

4

@Yoreki i did use those functions. I edited the post to add that information.

@kdgalla The shader has a default texture i made to see the output. But as far as i can see, the material does not.

Edit : here is the custom shader graph i’m trying to use :

1 Like
5

Oh, I missed the part where you said you were using ShaderGraph. I imagine SetTexture should still work but, unfortunately, I don’t really know ShaderGraph so I may not be able to help troubleshoot the issue.

6

@kdgalla well, i have only superficial shader knowledge. so for me the shader graph is easier to use. I did take a look at the compiled result of the shader, but it made less sense than the UI.

7

Ok, just found out the problem. In the shader graph, the node name is not the field name in the function. when i replaced “_MainTex” by “Texture2D_97802B5C”, which is the reference, it worked properly.

Edit : and of course, when i changed the reference to _MainTex, mat.mainTexture works properly too.

7 Likes
8

You just saved my life!

1 Like
9

Thanks a lot @madks13 , it was the same problem I was getting as well.
In case someone is new with Shadergraph too, the reference name can be found here.9737479--1392757--upload_2024-3-29_13-37-28.png

1 Like