**Function: shades a cube with a different color for each edge.

FVS-ColorCube.shader

/* by FVS - Ha Luan */
// Usage:
// 1. Create a material using this shader
// 2. Apply the new material to a cube with correct normal vectors defined (a Unity's built-in cube is enough)
Shader "FVS/Color cube" {

	SubShader
	{
		
			cull off
			Pass
			{
				CGPROGRAM
					#pragma vertex vert
					#pragma fragment frag

					struct appdata_t
					{
						float4 vertex : POSITION;
						float4 normal : NORMAL;
						fixed4 color : COLOR;
					};

					struct v2f
					{
						float4 vertex : SV_POSITION;
						fixed4 color : COLOR;
					};

					v2f vert(appdata_t v)
					{
						v2f o;
						o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);

						float r;
						float g;
						float b;

						// r,x
						if (v.normal.x > 0)
						{
							r = 1;
						}
						else if (v.normal.x < 0)
						{
							r = 0;
						}
						else
						{
							r = 0.5;
						}

						// g,y
						if (v.normal.y > 0)
						{
							g = 1;
						}
						else if (v.normal.y < 0)
						{
							g = 0;
						}
						else
						{
							g = 0.5;
						}

						// b,z
						if (v.normal.z > 0)
						{
							b = 1;
						}
						else if (v.normal.z < 0)
						{
							b = 0;
						}
						else
						{
							b = 0.5;
						}

						///
						if (v.normal.y == 0)
						{
							o.color = fixed4(r, g + v.vertex.y, b, 1);
						}
						else
						{
							o.color = fixed4(r, g + v.vertex.z, b, 1);
						}
						

						///
						return o;
					}

					fixed4 frag(v2f i) : SV_Target
					{
						return i.color;
					}
				ENDCG
			}
	}
}