Hello everyone.
I’ve been reading about shaders with CG lately and doing pretty good I suppose. But the last tutorial I’ve watched created some questions. So here it is.
This is the tutorial : 06c – Adding Textures Practical
And here is the result
Shader "unityCookie/tut/beginner/6 - Texture Map"
{
Properties
{
_Color ("Color Tint", Color) = (1.0, 1.0, 1.0, 1.0)
_MainTex ("Diffuse Texture", 2D) = "white"{}
_SpecColor ("Specular Color", Color) = (1.0, 1.0, 1.0, 1.0)
_Shininess ("Shininess", Float) = 10
_RimColor ("Rim Color", Color) = (1.0, 1.0, 1.0, 1.0)
_RimPower ("Rim Power", Range(0.1, 10.0)) = 3.0
}
SubShader
{
Pass
{
Tags { "LightMode" = "ForwardBase"}
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
//#pragma exclude_renderers flash
//user defined variables
uniform sampler2D _MainTex;
uniform float4 _MainTex_ST;
uniform float4 _Color;
uniform float4 _SpecColor;
uniform float4 _RimColor;
uniform float _Shininess;
uniform float _RimPower;
// unity defined variables
uniform float4 _LightColor0;
// base input structs
struct vertexInput
{
float4 vertex : POSITION;
float3 normal : NORMAL;
float4 texcoord : TEXCOORD0;
};
struct vertexOutput
{
float4 pos : SV_POSITION;
float4 tex : TEXCOORD0;
float4 posWorld : TEXCOORD1;
float3 normalDir : TEXCOORD2;
};
// vertex function
vertexOutput vert(vertexInput v)
{
vertexOutput o;
o.posWorld = mul(_Object2World, v.vertex);
o.normalDir = normalize(mul(float4(v.normal, 0.0), _World2Object).xyz);
o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
o.tex = v.texcoord;
return o;
}
// fragment function
float4 frag(vertexOutput i):COLOR
{
float3 normalDirection = i.normalDir;
float3 viewDirection = normalize(_WorldSpaceCameraPos.xyz - i.posWorld.xyz);
float3 lightDirection;
float atten;
if(_WorldSpaceLightPos0.w == 0.0) // directional light
{
atten = 1.0;
lightDirection = normalize(_WorldSpaceLightPos0.xyz);
}
else
{
float3 fragmentToLightSource = _WorldSpaceLightPos0.xyz - i.posWorld.xyz;
float distance = length(fragmentToLightSource);
atten = 1.0/distance;
lightDirection = normalize(fragmentToLightSource);
}
// Lighting
float3 diffuseReflection = atten * _LightColor0.xyz * saturate(dot(normalDirection, lightDirection));
float3 specularReflection = diffuseReflection * _SpecColor.xyz * pow(saturate(dot(reflect(-lightDirection, normalDirection), viewDirection)), _Shininess);
//Rim lighting
float rim = 1 - saturate(dot(viewDirection, normalDirection));
float3 rimLighting = saturate(dot(normalDirection, lightDirection) * _RimColor.xyz * _LightColor0.xyz * pow( rim, _RimPower ) );
float3 lightFinal = UNITY_LIGHTMODEL_AMBIENT.xyz + diffuseReflection + specularReflection + rimLighting;
// Texture Maps
float4 tex = tex2D(_MainTex, i.tex.xy * _MainTex_ST.xy + _MainTex_ST.zw);
return float4(tex.xyz * lightFinal * _Color.xyz, 1.0);
}
ENDCG
}
Pass
{
Tags { "LightMode" = "ForwardAdd"} // pass for additional light sources
Blend One One // Additive blending
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
//#pragma exclude_renderers flash
//user defined variables
uniform sampler2D _MainTex;
uniform float4 _MainTex_ST;
uniform float4 _Color;
uniform float4 _SpecColor;
uniform float4 _RimColor;
uniform float _Shininess;
uniform float _RimPower;
// unity defined variables
uniform float4 _LightColor0;
// base input structs
struct vertexInput
{
float4 vertex : POSITION;
float3 normal : NORMAL;
float4 texcoord : TEXCOORD0;
};
struct vertexOutput
{
float4 pos : SV_POSITION;
float4 tex : TEXCOORD0;
float4 posWorld : TEXCOORD1;
float3 normalDir : TEXCOORD2;
};
// vertex function
vertexOutput vert(vertexInput v)
{
vertexOutput o;
o.posWorld = mul(_Object2World, v.vertex);
o.normalDir = normalize(mul(float4(v.normal, 0.0), _World2Object).xyz);
o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
o.tex = v.texcoord;
return o;
}
// fragment function
float4 frag(vertexOutput i):COLOR
{
float3 normalDirection = i.normalDir;
float3 viewDirection = normalize(_WorldSpaceCameraPos.xyz - i.posWorld.xyz);
float3 lightDirection;
float atten;
if(_WorldSpaceLightPos0.w == 0.0) // directional light
{
atten = 1.0;
lightDirection = normalize(_WorldSpaceLightPos0.xyz);
}
else
{
float3 fragmentToLightSource = _WorldSpaceLightPos0.xyz - i.posWorld.xyz;
float distance = length(fragmentToLightSource);
atten = 1.0/distance;
lightDirection = normalize(fragmentToLightSource);
}
// Lighting
float3 diffuseReflection = atten * _LightColor0.xyz * saturate(dot(normalDirection, lightDirection));
float3 specularReflection = diffuseReflection * _SpecColor.xyz * pow(saturate(dot(reflect(-lightDirection, normalDirection), viewDirection)), _Shininess);
//Rim lighting
float rim = 1 - saturate(dot(viewDirection, normalDirection));
float3 rimLighting = saturate(dot(normalDirection, lightDirection) * _RimColor.xyz * _LightColor0.xyz * pow( rim, _RimPower ) );
float3 lightFinal = diffuseReflection + specularReflection + rimLighting;
// Texture Maps
float4 tex = tex2D(_MainTex, i.tex.xy * _MainTex_ST.xy + _MainTex_ST.zw);
return float4(lightFinal * _Color.xyz, 1.0);
}
ENDCG
}
}
// Fallback "Specular"
}
Problem is, at the last return. Where the extra light hits I get the default material color and not the texture. To keep the texture I found that it works with :
return float4(tex.xyz * lightFinal * _Color.xyz, 1.0);
Is this the way to do this or have I done something wrong?
Thanks for reading this.
Bonus question: Is CG language worth the time to learn?
.