Hi all,
I've been struggling, drawing, calculating and can finally say I have a fully working lighting shader;
- multiple directional lights
- multiple point lights
- forward rendering
- static number of lights, different effect files (no unrolling loops)
- diffuse and specular (blinn phong, using half angle)
- single texture
No copy/pasting, but fully understanding all the math 
The normals I'm sending into the VS are normalized, so I've skipped normalizing the normal in the VS.
I think I've moved as much calculations as possible from the PS to the VS, to prevent wasting cycles.
My question; do you see any 'high level' chances of optimization?
(I'm not looking for micro optimizations, just stupid/ things I've overlooked)
The specular highlights are now the color of the source light, unfortunately this introduced 2 new float3's just for the specular highlight color (for both directional and point lights). Don't know if there's an easier way, assuming that non-metals specular highlights take over the color of the light source.
Any input is really appreciated.
/*************************************************************/
/** CR GENERIC SHADER 1 DIRECTIONAL, 8 POINT LIGHTS **/
/** PER PIXEL LIGHTING **/
/** AMBIENT, DIFFUSE, SPECULAR **/
/** SINGLE TEXTURE, ANISOTROPY **/
/** TECHNIQUES: OPAQUE AND BLENDED **/
/** SHADER MODEL: 3.0,NO BWARDS COMPATIBILITY **/
/*************************************************************/
/*******************************************************/
/** UNIFORM INPUT, CONTROLLED BY ENGINE **/
/** TRANSFORMATIONS & MATERIALS **/
/*******************************************************/
uniform extern float4x4 World : WORLD;
uniform extern shared float4x4 ViewProj : VIEWPROJECTION;
uniform extern shared float3 CameraPos : CAMERAPOS;
uniform extern float3 AmbientColInt : AMB_COLOR_INTENSITY;
uniform extern float4 MatDiff : MATERIAL_DIFFUSE;
uniform extern float4 MatSpec : MATERIAL_SPECULAR;
uniform extern float4 MatEmi : MATERIAL_EMISSIVE;
uniform extern float MatSpecPower : MATERIAL_POWER;
uniform extern texture Tex0 : TEXTURE0 < string name = "roadblock texture.tga"; >;
// modelfile, just for effectedit
string XFile = "roadblock.x";
/*******************************************************/
/** UNIFORM INPUT, CONTROLLED BY ENGINE **/
/** LIGHT SOURCES AND PROPERTIES **/
/*******************************************************/
#define MaxDirectionalLights 1
extern float3 DirLightDir[MaxDirectionalLights];
extern float3 DirLightColInt[MaxDirectionalLights];
#define MaxPointLights 8
extern float3 PointLightPos[MaxPointLights];
extern float PointLightRange[MaxPointLights];
extern float PointLightFPRange[MaxPointLights];
extern float3 PointLightColInt[MaxPointLights];
/*******************************************************/
/** SAMPLER STATES FOR TEXTURING **/
/*******************************************************/
sampler2D textureSampler = sampler_state
{
Texture = (Tex0);
MinFilter = ANISOTROPIC;
MagFilter = LINEAR;
MipFilter = LINEAR;
MaxAnisotropy = 4;
};
/*******************************************************/
/** VERTEX SHADER INPUT <= VERTEX DECLARATION **/
/*******************************************************/
struct VS_INPUT
{
float4 Pos : POSITION0;
float4 Normal : NORMAL0;
float2 TexCoord : TEXCOORD0;
};
/*******************************************************/
/** VERTEX SHADER OUTPUT - PIXEL SHADER INPUT **/
/*******************************************************/
struct VS_OUTPUT
{
float4 Pos : POSITION0;
float3 Normal : TEXCOORD1;
float2 TexCoord : TEXCOORD2;
float3 wPos : TEXCOORD3;
float3 ViewDir : TEXCOORD4;
};
/*******************************************************/
/** VERTEX SHADER PROGRAM **/
/*******************************************************/
VS_OUTPUT VS_function(VS_INPUT input)
{
VS_OUTPUT Out = (VS_OUTPUT)0;
float4 worldPosition = mul(input.Pos, World);
Out.Pos = mul(worldPosition, ViewProj);
Out.Normal = mul(input.Normal, (float3x3)World); // VS input = already normalized
Out.TexCoord = input.TexCoord;
Out.wPos = worldPosition.xyz;
Out.ViewDir = normalize(CameraPos - Out.wPos);
return Out;
}
/*******************************************************/
/** PIXEL SHADER PROGRAM **/
/*******************************************************/
float4 PS_function(VS_OUTPUT input): COLOR0
{
float4 textureColor = tex2D(textureSampler, input.TexCoord);
float3 normal = normalize(input.Normal);
/** DIRECTIONAL LIGHTS - PER PIXEL (DIFFUSE & SPECULAR) **/
float3 diffuseDir = 0.0f;
float3 specularDir = 0.0f;
for(int i=0;i<MaxDirectionalLights;i++)
{
diffuseDir += saturate(DirLightColInt[i] * dot(normal, DirLightDir[i]));
float3 lightdir = normalize(DirLightDir[i] - input.wPos);
float3 h = normalize(lightdir + input.ViewDir);
specularDir += (pow(saturate(dot(h, normal)), MatSpecPower) * DirLightColInt[i]);
/** DirLightColInt, should be just DirLightCol?? (no intensity) **/
}
/** POINT LIGHTS - PER PIXEL (DIFFUSE & SPECULAR) **/
float3 diffusePoint = 0.0f;
float3 specularPoint = 0.0f;
for(int i=0;i<MaxPointLights;++i)
{
float3 lightDir = normalize(PointLightPos[i] - input.wPos);
// PER PIXEL ATTENUATION
float dist = length(PointLightPos[i] - input.wPos);
float att = saturate(1 - ((dist - PointLightFPRange[0]) / (PointLightRange[0] - PointLightFPRange[0])));
/** WHY DO THIS, POWER OF 2, RANGE GETS SMALLER? **/
att *= att;
// DIFFUSE
float diffIntPoint = saturate(dot(normal, lightDir) * att);
diffusePoint += saturate(diffIntPoint * PointLightColInt[i]);
// SPECULAR; USING BLINN HALF ANGLE
float3 h = normalize(lightDir + input.ViewDir);
specularPoint += pow(saturate(dot(h, normal)), MatSpecPower) * att * PointLightColInt[i];
/** SPECULAR HIGHLIGHTS, currently non metals **/
/** **/
/** NON-METALS = SPEC COLOR = LIGHT COLOR **/
/** METALS = SPEC COLOR = MATERIAL SPEC COLOR **/
/** **/
/** CYCLES: WITH MAT SPEC COLOR, SPEC INTENSITY CAN BE FLOAT INSTEAD OF FLOAT3's **/
}
/** FINAL PIXEL COLOR (specular only for point lights **/
return float4((saturate(AmbientColInt + (MatDiff * (diffuseDir + diffusePoint)) + (MatSpec * (specularDir + specularPoint)) + MatEmi) * textureColor.rgb), textureColor.a);
}
/*******************************************************/
/** TECHNIQUES & PASSES **/
/*******************************************************/
technique OpaqueTechnique
{
pass P0
{
AlphaBlendEnable = FALSE;
VertexShader = compile vs_3_0 VS_function();
PixelShader = compile ps_3_0 PS_function();
}
}
/*******************************************************/
/** BLENDED **/
/*******************************************************/
technique BlendedTechnique
{
pass P0
{
AlphaBlendEnable = TRUE;
SrcBlend = SRCALPHA;
DestBlend = INVSRCALPHA;
AlphaOp[0] = SelectArg1;
AlphaArg1[0] = Texture;
VertexShader = compile vs_3_0 VS_function();
PixelShader = compile ps_3_0 PS_function();
}
}
