Hi, I am not confortable with Shaders, but what I want to do needs them. I want to create a chroma key shader to remove all the green part of a texture and replace it with alpha. Actually, I managed to remove all the green in the texture, but it removes all the green layer. I only need to keep the green layer on the picture inside my texture. (like a green background in the movies) Code (csharp): Shader "Custom/ChromaKey" { Properties { _MainTex ("Texture", 2D) = "white" {} _Color ("Color", Color) = (1,1,1,1) } SubShader { Tags { "RenderType" = "Transparent" } Lighting Off ZWrite Off Blend SrcAlpha OneMinusSrcAlpha CGPROGRAM #pragma surface surf Lambert sampler2D _MainTex; float4 _Color; struct Input { float2 uv_MainTex; }; void surf (Input IN, inout SurfaceOutput o) { half4 c = tex2D(_MainTex, IN.uv_MainTex); o.Albedo = c.rgb; o.Alpha = lerp(o.Albedo, _Color, c.g); } ENDCG } FallBack "Diffuse" } Thank you in advance for your help.