[SOLVED] Combining 2 textures into one

I’ll make this simple. What I want to achieve is putting a transparent texture on top of a non-transparent one which will serve as it’s background. Kinda like watermark. These textures are placed on cubes.

Currently I think that the problem is
that this lane
o.Albedo = backgroundTex+decalTex
can’t deal with
transparency and causes the problem below.


First of all I’d like to note that I have very little experience with shaders, so I would be really glad if someone could help me with this. (I feel like it shouldn’t be hard). The thing I want is easy. I want to combine 2 textures in a way shown below.


We were wrong about just adding the two colors: that would only work with black, rather than transparent.

I modified yours alot to make it clearer what changes I made. Also, that last line where I set o.Aplpha… options- might want to set it to 1.0, or the greater of the two texture alphas, or the multiplied product of the two alphas. EDIT: OP wanted an opaque final texture, and so removed the “alpha” from the #pragma surface line.

Shader "Custom/OreShader" {
     Properties {
         _Color ("Color", Color) = (1,1,1,1)
         _MainTex ("Main Texture Color (RGB)", 2D) = "white" {}
         _SecondaryTex ("Overlay Texture Color (RGB) Alpha (A)", 2D) = "white" {}
         _Glossiness ("Smoothness", Range(0,1)) = 0.5
         _Metallic ("Metallic", Range(0,1)) = 0.0
     SubShader {
         Tags { "RenderType"="Transparent"}

         LOD 200
         // Physically based Standard lighting model, and enable shadows on all light types
         #pragma surface surf Standard alpha fullforwardshadows
         // Use shader model 3.0 target, to get nicer looking lighting
         #pragma target 3.0
         sampler2D _MainTex;
         sampler2D _SecondaryTex;
         struct Input {
             float2 uv_MainTex;
			 //float2 uv_SecondTex;
         half _Glossiness;
         half _Metallic;
         fixed4 _Color;
         void surf (Input IN, inout SurfaceOutputStandard o) {
             // Albedo comes from a texture tinted by colora
             float4 mainTex = tex2D (_MainTex, IN.uv_MainTex);
             float4 overlayTex = tex2D (_SecondaryTex, IN.uv_MainTex);
		half3 mainTexVisible = mainTex.rgb * (1-overlayTex.a);
		half3 overlayTexVisible = overlayTex.rgb * (overlayTex.a);
		float3 finalColor = (mainTexVisible + overlayTexVisible) * _Color;
             o.Albedo = finalColor.rgb;
             // Metallic and smoothness come from slider variables
             o.Metallic = _Metallic;
             o.Smoothness = _Glossiness;
             o.Alpha = 0.5 * ( mainTex.a + overlayTex.a );
     FallBack "Diffuse"

You want to set the Non-Transparant texture on a separate layer.
For example, You put the Transparant texture on layer (-1) and the Non-Transparant on layer (0).

Set the Images you import to > Sprite Image.

Use photoshop to make your image transparant by lowering down the opacity. And maybe for example erasing a colour by selecting an Alpha colour and deleting it.