3 texture blend shader

Questions & Answers
1

Hello. Here is my modified 2 texture blend shader. I trying to add third texture but it is not working.

Shader “3 Texture Blend” {

        Properties {
            _Blend ("Blend", Range (0, 2)) = 0
            _MainTex1 ("Base1 (RGB)", 2D) = "white"
            _MainTex2 ("Base2 (RGB)", 2D) = "black"
            _MainTex3 ("Base3 (RGB)", 2D) = "red"
        }
        SubShader {
            Pass {
                SetTexture [_MainTex1]{}

  
                SetTexture [_MainTex2] {
                    constantColor (0, 0, 0, [_Blend])
                    combine texture lerp (constant) previous }
                    
                SetTexture [_MainTex3] {
                    constantColor (0, 0, 0, [_Blend])
                    combine texture lerp (constant) previous }
            }
        } 
    }

Help me please. I think maybe problem is in [_Blend].

2

Finally i figured how it can be.Thanks all! But now i dont know how to add Light Affection to Shader)

        Properties {
       		_Color ("Color Tint (A = Opacity)", Color) = (1,1,1,1)
            _Blend1 ("Blend", Range (0, 1)) = 0.0
            _Blend2 ("Blend", Range (0, 1)) = 0.0
            _MainTex1 ("Base (RGB)", 2D) = "red"
            _MainTex2 ("Base (RGB)", 2D) = "blue"
            _MainTex3 ("Base (RGB)", 2D) = "green"
        }
               
SubShader {
            Pass {
            	Lighting On  
            	ZWrite On
            	
            	Material {
                    Diffuse [_Color]
                    Ambient [_Color]
                }
                
                SetTexture [_MainTex1]{}
                    
                SetTexture [_MainTex2] {
                    constantColor (0, 0, 0, [_Blend1])
                    combine texture lerp (constant) previous 
                    }
                    

                    
                    
                SetTexture [_MainTex3] {
                    constantColor (0, 0, 0, [_Blend2])
                    combine texture lerp (constant) previous
                    }
                   
                         
            }
        } 
    }
3

I created a leaf shader that should blend between _Maintex (normal green) and _FallTex (yellow) and _WinterTex (bare branches) and came up with this

float4 texA = tex2D(_MainTex, uv_MainTex);
float4 texB = tex2D(_FallTex, uv_MainTex);
float4 texC = tex2D(_WinterTex, uv_MainTex);
float4 color = lerp(texA, lerp(texB, texC, step(0.6, _Blend)), step(0.3, _Blend));

Moving the _Blend value over 0.3 will show texB, and moving over 0.6 will show texC.