Demo 19 - Outline 3D model

Shader "Custom/Outline" {
    Properties {
        _MainTex ("MainTex", 2D) = "white" {}
        _Outline ("_Outline", Range(0,0.1)) = 0
        _OutlineColor ("Color", Color) = (1, 1, 1, 1)
    }
    SubShader {
        Pass {
            Tags { "RenderType"="Opaque" }
            Cull Front

            CGPROGRAM

            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"

            struct v2f {
                float4 pos : SV_POSITION;
            };

            float _Outline;
            float4 _OutlineColor;

            float4 vert(appdata_base v) : SV_POSITION {
                v2f o;
                o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
                float3 normal = mul((float3x3) UNITY_MATRIX_MV, v.normal);
                normal.x *= UNITY_MATRIX_P[0][0];
                normal.y *= UNITY_MATRIX_P[1][1];
                o.pos.xy += normal.xy * _Outline;
                return o.pos;
            }

            half4 frag(v2f i) : COLOR {
                return _OutlineColor;
            }

            ENDCG
        }

        CGPROGRAM
        #pragma surface surf Lambert

        sampler2D _MainTex;

        struct Input {
            float2 uv_MainTex;
        };

        void surf(Input IN, inout SurfaceOutput o) {
            o.Albedo = tex2D(_MainTex, IN.uv_MainTex);
        }

        ENDCG
    }
    FallBack "Diffuse"
}