I have a problem with the forwardAdd pass.
Compared to the base pass, it seems the forward add pass lights up to much, in other words, it light up the sprites more than their original color.
Another issue is when I have stacked sprites. Then the forward add pass adds the light from all objects I guess to the top one. Making it very bright.
I feel there is something Im doing wrong with the forward add pass.
Picture of issue is attached.
Shader:
Shader "Custom/TestShader2"
{
Properties
{
_MainTex ("Texture", 2D) = "white" {}
}
SubShader
{
Name "FORWARD"
Tags {
"LightMode" = "ForwardBase"
"Queue"="Transparent"
"RenderType"="Transparent"
}
Pass
{
Cull Off
ZWrite Off
Blend One OneMinusSrcAlpha
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma multi_compile_fog
#pragma multi_compile_fwdbase
#include "UnityCG.cginc"
uniform float4 _LightColor0;
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
half3 normal : NORMAL;
};
struct v2f
{
float2 uv : TEXCOORD0;
float4 vertex : SV_POSITION;
float3 worldPos : TEXCOORD1;
};
sampler2D _MainTex;
float4 _MainTex_ST;
v2f vert (appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;
o.uv = TRANSFORM_TEX(v.uv, _MainTex);
return o;
}
float3 Shade4Lights (
float4 lightPosX, float4 lightPosY, float4 lightPosZ,
float3 lightColor0, float3 lightColor1, float3 lightColor2, float3 lightColor3,
float4 lightAttenSq,
float3 pos)
{
// to light vectors
float4 toLightX = lightPosX - pos.x;
float4 toLightY = lightPosY - pos.y;
float4 toLightZ = lightPosZ - pos.z;
// squared lengths
float4 lengthSq = 0;
lengthSq += toLightX * toLightX;
lengthSq += toLightY * toLightY;
lengthSq += toLightZ * toLightZ;
// don't produce NaNs if some vertex position overlaps with the light
lengthSq = max(lengthSq, 0.000001);
// attenuation
float4 atten = 1.0 / (1.0 + lengthSq * lightAttenSq);
float4 diff = atten; //ndotl * atten;
// final color
float3 col = 0;
col += lightColor0 * diff.x;
col += lightColor1 * diff.y;
col += lightColor2 * diff.z;
col += lightColor3 * diff.w;
return col;
}
half3 GetAmbientLight()
{
return _LightColor0.rgb;
}
fixed4 frag (v2f i) : SV_Target
{
// sample the texture
fixed4 col = tex2D(_MainTex, i.uv);
half3 light = Shade4Lights(unity_4LightPosX0, unity_4LightPosY0, unity_4LightPosZ0, unity_LightColor[0], unity_LightColor[1], unity_LightColor[2], unity_LightColor[3], unity_4LightAtten0, i.worldPos);
half3 ambient = GetAmbientLight();
light = min((half3)1, ambient + light);
col.rgb *= light;
clip(col.a - 0.5);
return col;
}
ENDCG
}
Pass {
Tags { "LightMode" = "ForwardAdd" }
Cull Off
ZWrite Off
Blend One One
CGPROGRAM
#pragma multi_compile_fwdadd
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
#include "AutoLight.cginc"
uniform float4 _LightColor0;
struct vertexInput {
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
float3 normal : NORMAL;
};
struct vertexOutput {
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
float4 posWorld : TEXCOORD1;
float3 normalDir : TEXCOORD2;
LIGHTING_COORDS(3,4)
};
sampler2D _MainTex;
float4 _MainTex_ST;
vertexOutput vert(vertexInput v)
{
vertexOutput output;
output.uv = TRANSFORM_TEX(v.uv, _MainTex);
float4x4 modelMatrix = unity_ObjectToWorld;
float4x4 modelMatrixInverse = unity_WorldToObject;
output.posWorld = mul(modelMatrix, v.vertex);
output.normalDir = normalize(
mul(float4(v.normal, 0.0), modelMatrixInverse).xyz);
output.pos = UnityObjectToClipPos(v.vertex);
TRANSFER_VERTEX_TO_FRAGMENT(output);
return output;
}
#ifdef POINT
#define LIGHT_ATTENUATION_MOD(a) (tex2D(_LightTexture0, dot(a._LightCoord,a._LightCoord).rr).r)
#endif
float4 frag(vertexOutput input) : COLOR
{
float attenuation;
if (0.0 == _WorldSpaceLightPos0.w) // directional light?
{
attenuation = 1.0;
}
else // point or spot light
{
float2 vertexToLightSource =
_WorldSpaceLightPos0.xy - input.posWorld.xy;
float distance = length(vertexToLightSource);
distance = max(distance, 0.000001);
attenuation = LIGHT_ATTENUATION(input) / 2;
}
float3 diffuseLight = attenuation * _LightColor0.rgb;
fixed4 col = tex2D(_MainTex, input.uv);
col.rgb *= diffuseLight;
clip(col.a - 0.5);
return col;
}
ENDCG
}
}
}
