decal over Reflective/VertexLit

Unity Engine
1

Hello,

I have an online car game that I am trying to build a customer shader that will allow a decal on the car. What I did was take the unity source shader for Reflective/VertexLit and added another pass.

The texture shows up and its transparrent, but the problem I am having is that the color from the other pass gets added to the new texture. So if I had a red decal texture and set the color of the model to green the texture looks pink because its blending them together.

Sorry if the answer is obvious and thanks in advance for your help. I just started on modifying shaders and don’t have that much experience with them.

Here is the lines I added after the default passes:

Pass{
Name "Decal"
AlphaTest Greater 0.9
SetTexture [_DecalTex] { }
}

I have the following property set for the texture:

_DecalTex ("Decal (RGB) Transparency (A)", 2D) = "" {}

Here is the full source:

Shader "TLG/Reflective/VertexLit" {
Properties {
	_Color ("Main Color", Color) = (1,1,1,1)
	_SpecColor ("Spec Color", Color) = (1,1,1,1)
	_Shininess ("Shininess", Range (0.03, 1)) = 0.7
	_ReflectColor ("Reflection Color", Color) = (1,1,1,0.5)
	_MainTex ("Base (RGB) RefStrength (A)", 2D) = "white" {} 
	_DecalTex ("Decal (RGB) Transparency (A)", 2D) = "" {}
	_Cube ("Reflection Cubemap", Cube) = "_Skybox" { TexGen CubeReflect }
}

Category {
	Blend AppSrcAdd AppDstAdd
	Fog { Color [_AddFog] }
	
	
	// ------------------------------------------------------------------
	// ARB fragment program
	
	SubShader {
		// First pass does reflection cubemap
		Pass { 
			Cull Off
			Name "BASE"
			Tags {"LightMode" = "Always"}
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma fragmentoption ARB_fog_exp2
#pragma fragmentoption ARB_precision_hint_fastest
#include "UnityCG.cginc"

struct v2f {
	V2F_POS_FOG;
	float2 uv : TEXCOORD0;
	float3 I : TEXCOORD1;
};

uniform float4 _MainTex_ST;

v2f vert(appdata_tan v)
{
	v2f o;
	PositionFog( v.vertex, o.pos, o.fog );
	o.uv = TRANSFORM_TEX(v.texcoord,_MainTex);

	// calculate object space reflection vector	
	float3 viewDir = ObjSpaceViewDir( v.vertex );
	float3 I = reflect( -viewDir, v.normal );
	
	// transform to world space reflection vector
	o.I = mul( (float3x3)_Object2World, I );
	
	return o; 
}

uniform sampler2D _MainTex;
uniform samplerCUBE _Cube;
uniform float4 _ReflectColor;

half4 frag (v2f i) : COLOR
{
	half4 texcol = tex2D (_MainTex, i.uv);
	half4 reflcol = texCUBE( _Cube, i.I );
	reflcol *= texcol.a;
	return reflcol * _ReflectColor;
} 
ENDCG
		}
	
		
		// Second pass adds vertex lighting
		Pass {
			Lighting On
			Material {
				Diffuse [_Color]
				Emission [_PPLAmbient]
				Specular [_SpecColor]
				Shininess [_Shininess]
			}
			SeparateSpecular On
CGPROGRAM
#pragma fragment frag
#pragma fragmentoption ARB_fog_exp2
#pragma fragmentoption ARB_precision_hint_fastest

#include "UnityCG.cginc"

struct v2f {
	float2 uv : TEXCOORD0;
	float4 diff : COLOR0;
	float4 spec : COLOR1;
};

uniform sampler2D _MainTex : register(s0);
uniform float4 _ReflectColor;
uniform float4 _SpecColor;

half4 frag (v2f i) : COLOR
{
	half4 temp = tex2D (_MainTex, i.uv);	
	half4 c;
	c.xyz = (temp.xyz * i.diff.xyz + temp.w * i.spec.xyz ) * 2;
	c.w = temp.w * (i.diff.w + Luminance(i.spec.xyz) * _SpecColor.a);
	return c;
} 
ENDCG
			SetTexture[_MainTex] {}
		}

		Pass{
		Name "Decal"
		AlphaTest Greater 0.9
		SetTexture [_DecalTex] { }
		}
	}
	
	// ------------------------------------------------------------------
	// Radeon 9000
	
	SubShader {
	
		// First pass does reflection cubemap
		Pass { 
			Name "BASE"
			Tags {"LightMode" = "Always"}
CGPROGRAM
#pragma vertex vert
#include "UnityCG.cginc"

struct v2f {
	V2F_POS_FOG;
	float2 uv : TEXCOORD0;
	float3 I : TEXCOORD1;
};

uniform float4 _MainTex_ST;

v2f vert(appdata_tan v)
{
	v2f o;
	PositionFog( v.vertex, o.pos, o.fog );
	o.uv = TRANSFORM_TEX(v.texcoord,_MainTex);

	// calculate object space reflection vector	
	float3 viewDir = ObjSpaceViewDir( v.vertex );
	float3 I = reflect( -viewDir, v.normal );
	
	// transform to world space reflection vector
	o.I = mul( (float3x3)_Object2World, I );
	
	return o; 
}
ENDCG
			Program "" {
				SubProgram {
					Local 0, [_ReflectColor]
					"!!ATIfs1.0
					StartConstants;
						CONSTANT c0 = program.local[0];
					EndConstants;
					StartOutputPass;
						SampleMap r0, t0.str;
						SampleMap r1, t1.str;
						MUL r1, r1, r0.a;
						MUL r0, r1, c0;
					EndPass;
					"
				}
			}
			SetTexture [_MainTex] {combine texture}
			SetTexture [_Cube] {combine texture}
		}
		
		// Second pass adds vertex lighting
		Pass {
			Material {
				Diffuse [_Color]
				Ambient [_Color]
				Shininess [_Shininess]
				Specular [_SpecColor]
				Emission [_Emission]
			}
			Lighting On
			SeparateSpecular On
			SetTexture [_MainTex] {
				constantColor [_Color]
				Combine texture * previous DOUBLE, texture * constant
			}
		}
	}

	// ------------------------------------------------------------------
	// Old cards
	
	SubShader {
		Pass { 
			Name "BASE"
			Tags {"LightMode" = "Always"}
			Material {
				Diffuse [_Color]
				Ambient (1,1,1,1)
				Shininess [_Shininess]
				Specular [_SpecColor]
			}
			Lighting On
			SeparateSpecular on
			SetTexture [_MainTex] {
				combine texture * primary DOUBLE, texture * primary
			}
			SetTexture [_Cube] {
				combine texture * previous alpha + previous, previous
			}
		}
	}
}

// Fallback for cards that don't do cubemapping
FallBack "VertexLit", 1

}
2

I figured it out: (Blend SrcAlpha OneMinusSrcAlpha)

Pass{
	Blend SrcAlpha OneMinusSrcAlpha
	AlphaTest Greater 0.9
	SetTexture [_MuralTex] { 
	}
}

Now I just have to figure out how to only display the texture on 1 part of the model without having to break it into separate pieces.

3

that would require a second texture as blend mask or alternatively usage of the second UV channel and make it 0 where the texture is meant to vanish.
The first one is much more flexible but costs more performance

4

Yeah I’m using 3d studio max and I set different material ID’s and bring the model into the project. I can make 2 shaders and it would work fine, but I’m using the meshserializer and when bringing in the model with that it doesn’t recognize the different material id’s and each shader I add goes over the entire car. I’ll have to think of another way to do it.