Shader doesn't have a texture property '_MainTex'

Question

The wacky thing is I ran my code once and it worked like a charm. The line of code I'm getting the error on is:

exampleTexture = (Texture2D)rend.material.mainTexture;

I know that the custom shader I'm using has something other than 'mainTexture', it's something along the lines of:

Properties
    {
        _Example ("Example (R16)", 2D) = "black" {}
        _Color ("Color", Color) = (1, 1, 1, 1)
    }

I'm just stumped as it worked the first time, any ideas?

Answer 1

Well if you look into Material.mainTexture and also the source code you can see that there are two things this can refer to

• Either you have a shader property which is attributed with [MainTexture]
• or as fallback it is looking for _MainTex.

Or in the word of the API

By default, Unity considers a texture with the property name "_MainTex" to be the main texture. Use the [MainTexture] ShaderLab Properties attribute to make Unity consider a texture with a different property name to be the main texture.

Both is not the case in your shader.

You would probably want to rename Example to

_MainTex ("Example (R16)", 2D) = "black" {}

or if you want/need to stick to the name _Example you will need to add the mentioned attribute

 [MainTexture] _Example ("Example (R16)", 2D) = "black" {}

---

Or alternatively do not use the default property accessors but rather use the more generic Material.GetTexture

exampleTexture = (Texture2D)rend.material.GetTexture("_Example");