Dev: Implemented Complete Lighting Model for test Hair Material

AEspinosaDev · Nov 26, 2024 · e2b1e78 · e2b1e78
1 parent 2e3c5c7
commit e2b1e78
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Showing 3 changed files with 47 additions and 15 deletions.
diff --git a/include/engine/core/materials/hair_strand.h b/include/engine/core/materials/hair_strand.h
@@ -30,7 +30,7 @@ class HairStrandMaterial : public IMaterial
     bool  m_TT       = true; // Transmitance
     float m_TTpower  = 1.0f;
     bool  m_TRT      = true; // Second reflection
-    float m_TRTpower = 3.0f;
+    float m_TRTpower = 2.0f;
 
     float m_roughness = 0.4f;
     float m_scatter   = 7.0f;
@@ -252,6 +252,8 @@ class HairStrandMaterial2 : public HairStrandMaterial
         m_textures[N2]      = new Texture(settings);
         m_textures[GI]      = new Texture(settings);
         m_textures[MGI]     = new Texture(settings);
+        m_textures[NGI]     = new Texture(settings);
+        m_textures[NGI_TRT] = new Texture(settings);
         Tools::Loaders::load_texture(
             m_textures[N1], ENGINE_RESOURCES_PATH "textures/N_TT_R.png", TEXTURE_FORMAT_TYPE_NORMAL, false);
         Tools::Loaders::load_texture(
@@ -271,6 +273,7 @@ class HairStrandMaterial2 : public HairStrandMaterial
         m_textureBindingState[NGI]     = false;
         m_textureBindingState[NGI_TRT] = false;
         m_isDirty                      = true;
+        m_useScatter                   = true;
     }
 };
 } // namespace Core

diff --git a/resources/shaders/forward/hair_strand2.glsl b/resources/shaders/forward/hair_strand2.glsl
@@ -177,20 +177,27 @@ vec3 computeAmbient(vec3 n) {
                 s, 0.0, c);
         vec3 rotatedNormal = normalize(rotationY * n);
 
-        // ambient = evalMarschnerLookupBSDF(
-        //         rotatedNormal, 
-        //         normalize(-g_pos),
-        //         texture(irradianceMap, rotatedNormal).rgb*scene.ambientIntensity,
-        //         bsdf, 
-        //         nTex1,
-        //         nTex2,
-        //         GITex,
-        //         material.r, 
-        //         false,  //Take oput transmitance
-        //         material.trt);
+        ambient = evalMarschnerLookupBSDF(
+                rotatedNormal, 
+                normalize(-g_pos),
+                texture(irradianceMap, rotatedNormal).rgb*scene.ambientIntensity,
+                bsdf, 
+                nTex1,
+                nTex2,
+                GITex,
+                mGITex,
+                nGITex1,
+                nGITex2,
+                vec3(0.5),
+                vec3(0.5),
+                0.1,
+                material.r, 
+                false, 
+                material.trt,
+                material.useScatter);
 
 
-        ambient = (scene.ambientIntensity * scene.ambientColor) ;
+        // ambient = (scene.ambientIntensity * scene.ambientColor) ;
     }else{
         ambient = (scene.ambientIntensity * scene.ambientColor) ;
     }
@@ -238,7 +245,8 @@ void main() {
                 directFraction,
                 material.r, 
                 material.tt, 
-                material.trt);
+                material.trt,
+                material.useScatter);
 
             color += lighting;
         }

diff --git a/resources/shaders/scripts/BRDFs/marschner_LUT_BSDF.glsl b/resources/shaders/scripts/BRDFs/marschner_LUT_BSDF.glsl
@@ -117,7 +117,8 @@ vec3 evalMarschnerLookupBSDF(
     float directFraction,
     bool r,
     bool tt, 
-    bool trt) 
+    bool trt,
+	bool scatter) 
     {
 
     //Theta
@@ -168,6 +169,7 @@ vec3 evalMarschnerLookupBSDF(
 
     vec3 color          = R+TT+TRT;
 
+	if(scatter){
     //////////////////////////////////////////////////////////////////////////
 	// Local Scattering
 	//////////////////////////////////////////////////////////////////////////
@@ -187,9 +189,28 @@ vec3 evalMarschnerLookupBSDF(
 	// Global Scattering
 	//////////////////////////////////////////////////////////////////////////
 
+	vec3 trans = transDirect - directFraction;
 
+	//N
+	vec4  N_GI 		= texture(texGI_N, index1 );
+	float NR_GI   	= N_GI.a;
+	vec3  NTT_GI  	= N_GI.rgb;
+	vec3  NTRT_GI 	= texture(texGI_NTRT, index2 ).rgb;
 
+	//M
+	vec3 M_GIr 		= texture(texGI_M, vec2(ix_spread.r, 1-ix_thH) ).xyz;
+	vec3 M_GIg 		= texture(texGI_M, vec2(ix_spread.g, 1-ix_thH) ).xyz;
+	vec3 M_GIb 		= texture(texGI_M, vec2(ix_spread.b, 1-ix_thH) ).xyz;
 
+	vec3 MR_GI   	= vec3( M_GIr.x, M_GIg.x, M_GIb.x );
+	vec3 MTT_GI  	= vec3( M_GIr.y, M_GIg.y, M_GIb.y );
+	vec3 MTRT_GI 	= vec3( M_GIr.z, M_GIg.z, M_GIb.z );
+
+	vec3 f_indir = trans * DENSITY * ( gi + MR_GI*NR_GI + MTT_GI*NTT_GI + MTRT_GI*NTRT_GI );	// N components already divided by PI
+	color +=  f_indir;
+
+	// color += gi * 0.1; 
+	}
 	//////////////////////////////////////////////////////////////////////////
 
     return              color * irradiance * GLOBAL_SCALE;