BarycentricWireframeUv1

The following shader assumes that you have mesh.uv1 set to barycentric uvs. You can set the line width, line color, and grid color.

	public Vector2[] GetBarycentricFixed()
	{
		Vector2[] uvs =
			new Vector2[4];
		
		const int topLeft = 0;
		const int topRight = 1;
		const int bottomLeft = 2;
		const int bottomRight = 3;
		
		uvs[topLeft] = new Vector2(0,0);
		uvs[topRight] = new Vector2(1,0);
		uvs[bottomLeft] = new Vector2(0,1);
		uvs[bottomRight] = new Vector2(1,1);
		
		return uvs;
	}

Shader "BarycentricWireframeUv1" {
	Properties {
		_LineColor ("Line Color", Color) = (1,1,1,1)
		_GridColor ("Grid Color", Color) = (0,0,0,0)
		_LineWidth ("Line Width", float) = 0.1
	}
	SubShader {
        Pass {

CGPROGRAM

#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"

uniform float4 _LineColor;
uniform float4 _GridColor;
uniform float _LineWidth;

// vertex input: position, uv1, uv2
struct appdata {
    float4 vertex : POSITION;
    float4 texcoord1 : TEXCOORD1;
    float4 color : COLOR;
};

struct v2f {
    float4 pos : POSITION;
    float4 texcoord1 : TEXCOORD1;
    float4 color : COLOR;
};

v2f vert (appdata v) {
    v2f o;
    o.pos = mul( glstate.matrix.mvp, v.vertex);
    o.texcoord1 = v.texcoord1;
    o.color = v.color;
    return o;
}

float4 frag(v2f i ) : COLOR
{
	if (i.texcoord1.x < _LineWidth ||
		i.texcoord1.y < _LineWidth)
	{
		return _LineColor;
	}
	
	if ((i.texcoord1.x - i.texcoord1.y) < _LineWidth &&
		(i.texcoord1.y - i.texcoord1.x) < _LineWidth)
	{
		return _LineColor;
	}
	else
	{
		return _GridColor;
	}
}

ENDCG

        }
	} 
	Fallback "Vertex Colored", 1
}