Hello,
I tried to make a double sided cloth I partially downloaded and partially wrote shader for double sided material. Also tried thin box, double faced mesh, two separated cloths. But all lead to bad cloth physics, normal issues, or separated simulation for both cloths… The best solution is this shader at this moment. But it has one issue as unity render depth separately, it just ignore backfaces of the mesh. And then shadows behind the cloth appears onto the flag (like shadows of the building behind the flag, which should not appear, because it is behind the flag). It also shows fog, SSAO and all other things that uses depth… Partial sollution is to turn off shadows on renderer. But it has 2 problems. 1st there are no shadows, and still other depth based things will stay incorrect.
Do you have any solution, how to tell depth render to not cull backface? Or how to do simple double sided cloth for flags? I tried at least 8 approaches and all fails even more… Also with Depth render I found that almost every water in unity has problem to correctly draw underwater fog. It ignores end of the water and ray stops on the mountains… So if anyone has solution also for this problem I would be happy 
but fortunately my game is not much underwater… these flags are more crucial…
Thanks
Jakub
Shader "Custom/2 Sided" {
Properties {
_Color ("Color", Color) = (1,1,1,1)
_MainTex ("Albedo (RGB)", 2D) = "white" {}
_Glossiness ("Smoothness", Range(0,1)) = 0.5
_Metallic ("Metallic", Range(0,1)) = 0.0
_BumpMap("Normal Map", 2D) = "bump" {}
_BumpScale("Scale", Float) = 1.0
// _Parallax ("Height Scale", Range (0.005, 0.08)) = 0.02
// _ParallaxMap ("Height Map", 2D) = "black" {}
}
SubShader {
Tags { "RenderType"="Opaque" }
LOD 300
Cull Back
// Fog {Mode Off}
// ZWrite On
//usePass"Custom/TransparentShadowReceiver"
CGPROGRAM
// Physically based Standard lighting model, and enable shadows on all light types
#pragma surface surf Standard fullforwardshadows // alpha
#pragma target 3.0
sampler2D _MainTex;
sampler2D _BumpMap;
struct Input {
float2 uv_MainTex;
};
half _Glossiness;
half _Metallic;
half _BumpScale;
fixed4 _Color;
void surf (Input IN, inout SurfaceOutputStandard o) {
// Albedo comes from a texture tinted by color
fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;
o.Albedo = c.rgb;
// Metallic and smoothness come from slider variables
o.Normal=UnpackScaleNormal(tex2D(_BumpMap, IN.uv_MainTex),_BumpScale);
o.Metallic = _Metallic;
o.Smoothness = _Glossiness;
o.Alpha = c.a;
}
ENDCG
// Tags { "LightMode"="Vertex" }
Ztest LEqual
Cull Front
// Fog {Mode Off}
CGPROGRAM
#pragma surface surf Standard fullforwardshadows approxview //alpha
// #pragma multi_compile_fwdbase
#pragma target 3.0
#pragma vertex vert
sampler2D _MainTex;
sampler2D _BumpMap;
struct Input {
float2 uv_MainTex;
fixed facing :VFACE;
};
half _Glossiness;
half _Metallic;
fixed4 _Color;
half _BumpScale;
void vert (inout appdata_full v) {
// v.normal *= -1;
v.tangent*=-1;
}
void surf (Input IN, inout SurfaceOutputStandard o) {
// Albedo comes from a texture tinted by color
fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;
o.Albedo = c.rgb;
// Metallic and smoothness come from slider variables
o.Metallic = _Metallic;
o.Smoothness = _Glossiness;
o.Alpha = c.a;
o.Normal=UnpackScaleNormal(tex2D(_BumpMap, IN.uv_MainTex),_BumpScale);
o.Normal.z*=IN.facing;
}
ENDCG
//
}
FallBack "Diffuse"
}