# DX11 DX11 Uber Shading - Lighting

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Hi guys,

right now I'm facing a problem with lighting in Uber Shading, my Shader file looks as following:

cbuffer ConstantObjectBuffer
{
float4x4 final;
float4x4 rotation;
float4 ambientcol;
}

cbuffer ConstantFrameBuffer
{
float4 lightvec;
float4 lightcol;
}

cbuffer UberData
{
int _diffuse;
int _texture;
int _directionall;
int _bumpmap;
}

cbuffer ConstantMatrixBuffer
{
float4 world;
float4 view;
float4 projection;
}

Texture2D txt;
Texture2D txt2;
SamplerState ss;

struct VOut
{
float4 position : SV_POSITION;
float2 texcoord : TEXCOORD;    // texture coordinates
float4 normal : NORMAL;
float4 color : COLOR;
};

VOut VShader(float4 position : POSITION, float4 normal : NORMAL, float2 texcoord : TEXCOORD)
{
VOut output;
output.position = mul(final, position);

output.color = float4(0, 0, 0, 1);

// set the ambient light
if (_diffuse == 1)
{
output.color = ambientcol;
}

if (_texture == 1)
{
output.texcoord = texcoord;
}

if (_directionall == 1)
{
float4 norm = normalize(mul(rotation, normal));
float diffusebrightness = saturate(dot(norm, lightvec));
output.color += lightcol * diffusebrightness;

float4 light = normalize(lightvec);
float4 eye = float4(1.0, 1.0, 1.0, 0.0);
float4 vhalf = normalize(light + eye);

float4 specularMaterial = float4(1, 1, 1, 1.0);
float specular = dot(normal, vhalf);

output.color += specular*specularMaterial;
}

return output;
}

{
float4 color = input.color;

if (_texture == 1)
{
color *= txt.Sample(ss, input.texcoord);
}

return color;
}


As you can see I have a section of lighting, and this Shader file is used once per mesh. But the problem is what if I have more than one light? Maybe 3? As hlsl cannot declare dynamic arrays, is the only option to have limited lights?

I am aware of this deffered rendering, just not how it works, though I can't say I have put a lot of research effort into that, but would that fit here?

Thank You

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Yup!  Deferred shading is great for large numbers of light sources of varying magnitudes, sizes and intensities.

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As hlsl cannot declare dynamic arrays, is the only option to have limited lights?

You can declare the array to be some limited size, n, and then if you have more than n lights, you can render the model in ceil(lights / n) passes. The first pass can be opaque, and then every successive pass can be additively blended over the top.

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