3 issues - cubemap to toonramp, alpha and load default texture

Hello,

I'm trying to adapt my toon lit shader and need some help.

1) How I move from cube map to toon ramp ? I put the variable, but actually don't have idea how implement it
2) The alpha texture not work correctly, probably I need to use other operator
3) When I define a default value for property (like gray on ramp, can I use a file path for default value, like /assets/shader/toon-ramp1.png) ???

Code (CSharp):

1.  
2. Shader "Piglet/Toon Lit Alpha" {
3.      Properties {
4.          _Color ("Main Color", Color) = (.5,.5,.5,1)
5.          _MainTex ("Base (RGB)", 2D) = "white" {}
6.          _ToonShade ("ToonShader Cubemap(RGB)", CUBE) = "" { Texgen CubeNormal }
7.          _Ramp ("Toon Ramp (RGB)", 2D) = "gray" {}
8.      }
9. SubShader {
10.      Tags { "RenderType"="Opaque" "Queue"="Transparent" }
11.      Pass {
12.          Name "BASE"
13.          Blend SrcAlpha OneMinusSrcAlpha
14.          CGPROGRAM
15.          #pragma vertex vert
16.          #pragma fragment frag
17.          #pragma fragmentoption ARB_precision_hint_fastest
18.          #include "UnityCG.cginc"
19.          sampler2D _MainTex;
20.          samplerCUBE _ToonShade;
21.          float4 _MainTex_ST;
22.          float4 _Color;
23.          struct appdata {
24.              float4 vertex : POSITION;
25.              float2 texcoord : TEXCOORD0;
26.              float3 normal : NORMAL;
27.          };
28.        
29.          struct v2f {
30.              float4 pos : POSITION;
31.              float2 texcoord : TEXCOORD0;
32.              float3 cubenormal : TEXCOORD1;
33.          };
34.          v2f vert (appdata v)
35.          {
36.              v2f o;
37.              o.pos = UnityObjectToClipPos (v.vertex);
38.              o.texcoord = TRANSFORM_TEX(v.texcoord, _MainTex);
39.              o.cubenormal = mul (UNITY_MATRIX_MV, float4(v.normal,0));
40.              return o;
41.          }
42.          float4 frag (v2f i) : COLOR
43.          {
44.              float4 col = _Color * tex2D(_MainTex, i.texcoord);
45.              float4 cube = texCUBE(_ToonShade, i.cubenormal);
46.              return float4(2.0f * cube.rgb * col.rgb, col.a);
47.          }
48.          ENDCG          
49.      }
50. }
51. SubShader {
52.      Tags { "RenderType"="Opaque" "Queue"="Transparent"}
53.      Pass {
54.          Name "BASE"
55.          SetTexture [_MainTex] {
56.              constantColor [_Color]
57.              Combine texture * constant
58.          }
59.          SetTexture [_ToonShade] {
60.              combine texture * previous DOUBLE, previous
61.          }
62.      }
63. }
64. Fallback "VertexLit"
65. }
66.  

 

Something like:
tex2D(rampTex, float2(dot(lightDir.normalized, i.normal. normalized), 0.5))
https://catlikecoding.com/unity/tutorials/rendering/part-4/
I think in your case is better move to matcap, not to ramp, because your shader don't have lighting calculation at all.

 

First of all, thanks for reply, but I really don't understand what exactly I need to do and about which of 3 points you reply