Unity - how to make material double sided - unity3d

Question

Search for the issue gives a number of solutions, but they don't work for some reason in mine Unity3D 5.4. Like
camera inside a sphere
I do not see cull and/or sides in material in Unity editor.
In C#
rend = GetComponent<Renderer>();
mater = rend.material;
rend.setFaceCulling( "front", "ccw" );
mater.side = THREE.DoubleSide;
gives no such setFaceCulling and side property.
How to make material double sided?

Answer 1

You need a custom shader to enable double sided material by using Cull Off
The easiest/fastest way to test is to create a new Standard Surface Shader in the editor and open it. Add the line Cull Off below LOD 200.
Now one thing to consider is that lightning will not render correctly for the back faces. If you want that, I would recommend doing models with 2 sides.

Answer 2

Use or create a shader with
Cull off
Seen here in this simple 2 sided shader:
Shader "Custom/NewSurfaceShader" {
Properties {
}
SubShader {
Cull off
Pass {
ColorMaterial AmbientAndDiffuse
}
}
}

Answer 3

Maybe my answer for your Unity Version doesn't work, but here it is a solution for newer versions in HDRP in image below

Answer 4

just Creat an Unlitshader and edit it:
you should write Cull off bellow LOD 100
then drag it to a new material and set an picture for test - now drag material to an object .
lightning will render correctly !!! ( my unity is 2019.4 )
enter code here
Shader "Unlit/unlit"
{
Properties
{
_MainTex ("Texture", 2D) = "white" {}
}
SubShader
{
Tags { "RenderType"="Opaque" }
LOD 100
Cull off
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma multi_compile_fog
#include "UnityCG.cginc"
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
struct v2f
{
float2 uv : TEXCOORD0;
UNITY_FOG_COORDS(1)
float4 vertex : SV_POSITION;
};
sampler2D _MainTex;
float4 _MainTex_ST;
v2f vert (appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = TRANSFORM_TEX(v.uv, _MainTex);
UNITY_TRANSFER_FOG(o,o.vertex);
return o;
}
fixed4 frag (v2f i) : SV_Target
{
// sample the texture
fixed4 col = tex2D(_MainTex, i.uv);
// apply fog
UNITY_APPLY_FOG(i.fogCoord, col);
return col;
}
ENDCG
} }}

Answer 5

Also, In Unity 2020.3 URP/Lit shader has a Render face option guys.

Answer 6

You may use a custom surface shader with Cull Off but the opposite faces will not get the light proper, because the normals are valid only for front faces, for back faces the normals are opposite to faces. If you want the back face to be treated like the front face and don't want to make a model with double sides mesh to consume double memory you can draw in 2 Passes, 1 Pass for front face and 1 for back face where you can inverse normal for every vertex in vertex shader. You can use Cull back and Cull front.
SubShader
{
//Here start first Pass, if you are using standard surface shader passes are created automated,
//else you should specify Pass { }
Tags { ... }
LOD 200
Cull Back
...
struct Input
{
...
}
...
...
//or vert & frag shaders
void surf(Input IN, inout SurfaceOutputStandard p)
{
//processing front face, culling back face
...
}
...
//Here start second pass put automated by unity
Tags {...}
LOD 200
Cull Front
#pragma vertex vert
#pragma surface ...
...
struct Input
{
...
}
...
void vert(inout appdata_full v)
{
v.normal = -v.normal;//flip
}
void surf(Input IN, inout SurfaceOutputStandard p)
{
//processing back face, culling front face
...
}
}