Other Adding an outline to a curved world shader

I’ve got a curved world shader and I want to add an outline to my objects.

I’m able to do a curved world and outline separately, but when I combine the two by adding a second pass to the curved shader, the problem is that the outline doesn’t curve along with the objects.

Here’s the shader code for this:

Code (CSharp):

1. Shader "Custom/Curved Shader"
2. {
3.     Properties
4.     {
5.         _Color ("Main Color", Color) = (1,1,1,1)
6.         _MainTex ("Base (RGB)", 2D) = "white" {}
7.  
8.         _OutlineColor ("Outline Color", Color) = (0, 0, 0, 1)
9.         _OutlineThickness ("Outline Thickness", Range(0,1)) = 0.1
10.     }
11.  
12.     SubShader
13.     {
14.         Tags { "RenderType"="Opaque" }
15.         LOD 150
16.  
17.         CGPROGRAM
18.  
19.         #pragma surface surf Lambert vertex:vert addshadow
20.  
21.         #include "UnityCG.cginc"
22.         #include "CurvedWorldCore.cginc"
23.  
24.         sampler2D _MainTex;
25.      
26.         struct Input
27.         {
28.             float2 uv_MainTex;
29.         };
30.  
31.         fixed4 _Color;
32.    
33.         void surf (Input IN, inout SurfaceOutput o)
34.         {
35.             fixed4 c = tex2D(_MainTex, IN.uv_MainTex) * _Color;
36.             o.Albedo = c.rgb;
37.             o.Alpha = c.a;
38.         }
39.  
40.         ENDCG
41.  
42.         Pass{
43.             Cull Front
44.  
45.             CGPROGRAM
46.  
47.             #include "UnityCG.cginc"
48.             #include "CurvedWorldCore.cginc"
49.  
50.             #pragma vertex vert
51.             #pragma fragment frag
52.  
53.             fixed4 _OutlineColor;
54.             float _OutlineThickness;
55.  
56.             struct appdata{
57.                 float4 vertex : POSITION;
58.                 float4 normal : NORMAL;
59.             };
60.  
61.             struct v2f{
62.                 float4 position : SV_POSITION;
63.             };
64.  
65.             v2f vert(appdata v){
66.                 v2f o;
67.                 o.position = UnityObjectToClipPos(v.vertex + normalize(v.normal) * _OutlineThickness);
68.                 return o;
69.             }
70.  
71.             fixed4 frag(v2f i) : SV_TARGET{
72.                 return _OutlineColor;
73.             }
74.  
75.             ENDCG
76.         }
77.     }
78.     FallBack "Mobile/VertexLit"
79. }
80.  

CurvedWorldCore.cginc

Code (CSharp):

1. float3 _Curvature;
2. float _Distance;
3.  
4. void vert(inout appdata_full v)
5. {              
6.     float4 vPos = mul( unity_ObjectToWorld, v.vertex);
7.  
8.     float dist = 0;
9.     dist = distance(vPos.z , _WorldSpaceCameraPos.z) - _Distance;
10.     if( dist < 0)    {    dist = 0;    }      
11.    
12.     float addY = dist * dist;
13.    
14.     vPos.y -= addY * _Curvature.y;
15.  
16.     dist = vPos.x - _WorldSpaceCameraPos.x;
17.     float addHY = dist * dist;
18.     vPos.y -= addHY* _Curvature.x ;
19.    
20.     // for corner
21.     vPos.x += addY * _Curvature.z;
22.  
23.     vPos = mul ( unity_WorldToObject, vPos);
24.     v.vertex = vPos;
25. }
26.  

CurvedWorld.cs

Code (CSharp):

1. public class CurvedWorld : MonoBehaviour {
2.  
3.     public Vector3 Curvature = new Vector3(0, 0.5f, 0);
4.     public float Distance = 0;
5.  
6.     [Space]
7.     public float CurvatureScaleUnit = 1000f;
8.    
9.     int CurvatureID;
10.     int DistanceID;
11.  
12.     private void OnEnable()
13.     {
14.         CurvatureID = Shader.PropertyToID("_Curvature");
15.         DistanceID = Shader.PropertyToID("_Distance");
16.     }
17.  
18.     void Update()
19.     {
20.         Vector3 curvature = CurvatureScaleUnit == 0 ? Curvature : Curvature / CurvatureScaleUnit;
21.  
22.         Shader.SetGlobalVector(CurvatureID, curvature);
23.         Shader.SetGlobalFloat(DistanceID, Distance);
24.     }
25. }
26.  

Another method I tried is by using this asset Quick Outline to create the outline via script rather than through a shader, but I get the same issue where the outline doesn’t curve.

I’m stuck as to how to fix this so I’d be grateful for some help with this issue.