I was inspired by a colleague to create this shader. So here it is. The shader uses an invisible plane to determine where the visibility line should be.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 |
Shader "Unlit/Ship" { Properties { _MainTex ("Texture", 2D) = "white" {} _OutlinePosition ("Outline Position", VECTOR) = (0,0,0,0) } SubShader { Tags { "Queue"="Transparent" } Pass { Blend SrcAlpha OneMinusSrcAlpha CGPROGRAM #pragma vertex vert #pragma fragment frag #include "UnityCG.cginc" struct appdata { float4 vertex : POSITION; float2 uv : TEXCOORD0; }; struct v2f { float4 vertex : SV_POSITION; float2 uv : TEXCOORD0; float3 planeWorldPos : TEXCOORD1; float3 planeWorldNormal : TEXCOORD2; float3 worldPos : TEXCOORD3; }; sampler2D _MainTex; float4 _MainTex_ST; float4 _OutlinePosition; v2f vert (appdata v) { v2f o; o.vertex = UnityObjectToClipPos(v.vertex); o.uv = TRANSFORM_TEX(v.uv, _MainTex); o.planeWorldPos = mul(unity_ObjectToWorld, _OutlinePosition); o.planeWorldNormal = mul(unity_ObjectToWorld, float3(0,0,1)); o.worldPos = mul(unity_ObjectToWorld, v.vertex); return o; } fixed4 frag (v2f i) : SV_Target { float3 planeWorldNormal = normalize(i.planeWorldNormal); float d = dot(i.planeWorldPos, planeWorldNormal); float d1 = dot(i.worldPos, planeWorldNormal); float dDelta = d1 - d; float t = 1.0 - pow(abs(dDelta) * 1.0, 0.2); fixed4 outlineCol = saturate(float4(t * 2.0, t * 4.0, t * 8.0, 1.0)); fixed4 col = tex2D(_MainTex, i.uv) + outlineCol; col.a = step(0.0, dDelta); return col; } ENDCG } } } |