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glitchy-engine-beef/GlitchyEditor/resources/Shaders/PBR.hlsl
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Simon Lübeß c1a87ed946 Separated Assets to Resources (Engine assets) and Assets (Project specific)
+ AssetHierarchy: Exposed RootNode
+ ContentBrowserWindow: Fixed Empty Folder not being Leaf-Node
+ TreeNode: Added IsParentOf, IsChildOf and IsInSubtree.
    + Fixed InternalDeleteTreeAndChildren for null trees
2023-07-30 20:30:06 +02:00

79 lines
2.1 KiB
HLSL

/*
* This File contains Function for PBR.
*/
#ifndef __PBR_HLSL__
#define __PBR_HLSL__
#include "ShaderHelpers.hlsl"
// #define PBR_IBL
/**
* Normal Distribution Function. (Trowbridge-Reits GGX)
* Calculates the relative surface area of microfacets exactly aligned to the halfway vector.
* @param normal The surface normal.
* @param halfway The halfway vector between the surface normal and the view direction.
* @param roughness Roughness value.
* @returns The relative surface area of microfacets exactly aligned to the halfway vector.
*/
float NormalDistributionGGX(float3 normal, float3 halfway, float roughness)
{
// Square roughness because it looks better
float a = roughness * roughness;
float aa = a * a;
float n_dot_h = max(dot(normal, halfway), 0.0f);
float denom = (n_dot_h * n_dot_h) * (aa - 1.0f) + 1.0f;
denom = PI * denom * denom;
return aa / denom;
}
/**
* Geometry Function calculating the overshadowing of microfacets based on roughness. (Schlick-Beckmann GGX).
* @param dot-product of normal vector and vector from surface to camera.
* @param k Roughness value.
*/
float GeometrySchlickGGX(float n_dot_v, float k)
{
return n_dot_v / (n_dot_v * (1 - k) + k);
}
/**
* Geometry Function calculating the overshadowing of microfacets based on roughness. (Smith)
* @param normal The surface normal.
* @param viewDir Vector from surface to viewer.
* @param lightDir Vector from surface to light source.
* @param roughness Roughness value.
*/
float GeometrySmith(float3 normal, float3 viewDir, float3 lightDir, float roughness)
{
#ifdef PBR_IBL
// IBL
float k = roughness * roughness / 2;
#else
// Direct lighting
float k = (roughness + 1.0f);
k = (k * k) / 8;
#endif
const float n_dot_v = max(dot(normal, viewDir), 0.0f);
float n_dot_l = max(dot(normal, lightDir), 0.0f);
return GeometrySchlickGGX(n_dot_v, k) * GeometrySchlickGGX(n_dot_l, k);
}
/**
* Calculates the fresnel value.
* @param n_dot_v Dot product of the normal and view direction
* @param F0 base reflectivity.
*/
float3 FresnelSchlick(float n_dot_v, float3 F0)
{
return F0 + (1.0 - F0) * pow(clamp(1.0 - n_dot_v, 0.0, 1.0), 5.0);
}
#endif // __PBR_HLSL__