Finished PBR IBL example

android/pbribl/build.py

@@ -7,48 +7,42 @@ import glob
 APK_NAME = "vulkanPBRIBL"
 SHADER_DIR = "pbribl"
 ASSETS_MODELS = ["cube.obj", "geosphere.obj", "teapot.dae", "torusknot.obj", "venus.fbx"]
-ASSETS_TEXTURES = ["hamarikyu_bridge_radiance_cube.ktx", "hamarikyu_bridge_irradiance_cube.ktx"]
+ASSETS_TEXTURES = ["hdr/pisa_cube.ktx"]
 
 if subprocess.call("ndk-build", shell=True) == 0:
     print("Build successful")
 
     # Assets
-    if not os.path.exists("./assets"):
+    os.makedirs("./assets/shaders/base", exist_ok=True)
-        os.makedirs("./assets")  
+    os.makedirs("./assets/shaders/%s" % SHADER_DIR, exist_ok=True)
+    os.makedirs("./assets/textures/hdr", exist_ok=True)
+    os.makedirs("./assets/models", exist_ok=True)
+    os.makedirs("./res/drawable", exist_ok=True)
 
     # Shaders
     # Base
-    if not os.path.exists("./assets/shaders/base"):
-        os.makedirs("./assets/shaders/base")           
     for file in glob.glob("../../data/shaders/base/*.spv"):
         shutil.copy(file, "./assets/shaders/base")
     # Sample
-    if not os.path.exists("./assets/shaders/%s" % SHADER_DIR):
-        os.makedirs("./assets/shaders/%s" % SHADER_DIR)
     for file in glob.glob("../../data/shaders/%s/*.spv" %SHADER_DIR):
         shutil.copy(file, "./assets/shaders/%s" % SHADER_DIR)
     # Textures
-    if not os.path.exists("./assets/textures"):
-        os.makedirs("./assets/textures")           
     for file in ASSETS_TEXTURES:
-        shutil.copy("../../data/textures/%s" % file, "./assets/textures")        
+        shutil.copy("../../data/textures/%s" % file, "./assets/textures/hdr")
     # Models
-    if not os.path.exists("./assets/models"):
-        os.makedirs("./assets/models")           
     for file in ASSETS_MODELS:
         shutil.copy("../../data/models/%s" % file, "./assets/models")
 
     # Icon
-    if not os.path.exists("./res/drawable"):
-        os.makedirs("./res/drawable")         
     shutil.copy("../../android/images/icon.png", "./res/drawable")
 
     if subprocess.call("ant debug -Dout.final.file=%s.apk" % APK_NAME, shell=True) == 0:
-        if len(sys.argv) > 1:
+        for arg in sys.argv[1:]:
-            if sys.argv[1] == "-deploy":
+            if arg == "-deploy":
                 if subprocess.call("adb install -r %s.apk" % APK_NAME, shell=True) != 0:
                     print("Could not deploy to device!")
     else:
         print("Error during build process!")
 else:
     print("Error building project!")
+    

data/shaders/pbribl/pbribl.frag

@@ -1,6 +1,3 @@
-// Phyiscally based rendering using IBL
-// Based on http://www.trentreed.net/blog/physically-based-shading-and-image-based-lighting/
-
 #version 450
 
 layout (location = 0) in vec3 inWorldPos;
@@ -14,10 +11,11 @@ layout (binding = 0) uniform UBO {
 	vec3 camPos;
 } ubo;
 
-layout (binding = 1) uniform UBOShared {
+layout (binding = 1) uniform UBOParams {
+	vec4 lights[4];
 	float exposure;
 	float gamma;
-} uboShared;
+} uboParams;
 
 layout(push_constant) uniform PushConsts {
 	layout(offset = 12) float roughness;
@@ -28,11 +26,15 @@ layout(push_constant) uniform PushConsts {
 	layout(offset = 32) float b;
 } material;
 
-layout (binding = 2) uniform samplerCube radianceMap;
+layout (binding = 2) uniform samplerCube samplerIrradiance;
-layout (binding = 3) uniform samplerCube irradianceMap;
+layout (binding = 3) uniform sampler2D samplerBRDFLUT;
+layout (binding = 4) uniform samplerCube prefilteredMap;
 
 layout (location = 0) out vec4 outColor;
 
+#define PI 3.1415926535897932384626433832795
+#define ALBEDO vec3(material.r, material.g, material.b)
+
 // From http://filmicgames.com/archives/75
 vec3 Uncharted2Tonemap(vec3 x)
 {
@@ -45,15 +47,72 @@ vec3 Uncharted2Tonemap( vec3 x )
 	return ((x*(A*x+C*B)+D*E)/(x*(A*x+B)+D*F))-E/F;
 }
 
-// Environment BRDF approximation from https://www.unrealengine.com/blog/physically-based-shading-on-mobile
+// Normal Distribution function --------------------------------------
-vec3 EnvBRDFApprox(vec3 SpecularColor, float Roughness, float NoV) 
+float D_GGX(float dotNH, float roughness)
 {
-	vec4 c0 = vec4(-1, -0.0275, -0.572, 0.022);
+	float alpha = roughness * roughness;
-	vec4 c1 = vec4(1, 0.0425, 1.04, -0.04);
+	float alpha2 = alpha * alpha;
-	vec4 r = Roughness * c0 + c1;
+	float denom = dotNH * dotNH * (alpha2 - 1.0) + 1.0;
-	float a004 = min(r.x * r.x, exp2(-9.28 * NoV)) * r.x + r.y;
+	return (alpha2)/(PI * denom*denom); 
-	vec2 AB = vec2(-1.04, 1.04) * a004 + r.zw;
+}
-	return SpecularColor * AB.x + AB.y;
+
+// Geometric Shadowing function --------------------------------------
+float G_SchlicksmithGGX(float dotNL, float dotNV, float roughness)
+{
+	float r = (roughness + 1.0);
+	float k = (r*r) / 8.0;
+	float GL = dotNL / (dotNL * (1.0 - k) + k);
+	float GV = dotNV / (dotNV * (1.0 - k) + k);
+	return GL * GV;
+}
+
+// Fresnel function ----------------------------------------------------
+vec3 F_Schlick(float cosTheta, vec3 F0)
+{
+	return F0 + (1.0 - F0) * pow(1.0 - cosTheta, 5.0);
+}
+vec3 F_SchlickR(float cosTheta, vec3 F0, float roughness)
+{
+	return F0 + (max(vec3(1.0 - roughness), F0) - F0) * pow(1.0 - cosTheta, 5.0);
+}
+
+vec3 prefilteredReflection(vec3 R, float roughness)
+{
+	const float MAX_REFLECTION_LOD = 9.0; // todo: param/const
+	float lod = roughness * MAX_REFLECTION_LOD;
+	float lodf = floor(lod);
+	float lodc = ceil(lod);
+	vec3 a = textureLod(prefilteredMap, R, lodf).rgb;
+	vec3 b = textureLod(prefilteredMap, R, lodc).rgb;
+	return mix(a, b, lod - lodf);
+}
+
+vec3 specularContribution(vec3 L, vec3 V, vec3 N, vec3 F0, float metallic, float roughness)
+{
+	// Precalculate vectors and dot products	
+	vec3 H = normalize (V + L);
+	float dotNH = clamp(dot(N, H), 0.0, 1.0);
+	float dotNV = clamp(dot(N, V), 0.0, 1.0);
+	float dotNL = clamp(dot(N, L), 0.0, 1.0);
+
+	// Light color fixed
+	vec3 lightColor = vec3(1.0);
+
+	vec3 color = vec3(0.0);
+
+	if (dotNL > 0.0) {
+		// D = Normal distribution (Distribution of the microfacets)
+		float D = D_GGX(dotNH, roughness); 
+		// G = Geometric shadowing term (Microfacets shadowing)
+		float G = G_SchlicksmithGGX(dotNL, dotNV, roughness);
+		// F = Fresnel factor (Reflectance depending on angle of incidence)
+		vec3 F = F_Schlick(dotNV, F0);		
+		vec3 spec = D * F * G / (4.0 * dotNL * dotNV + 0.001);		
+		vec3 kD = (vec3(1.0) - F) * (1.0 - metallic);			
+		color += (kD * ALBEDO / PI + spec) * dotNL;
+	}
+
+	return color;
 }
 
 void main()
@@ -62,31 +121,42 @@ void main()
 	vec3 V = normalize(ubo.camPos - inWorldPos);
 	vec3 R = reflect(-V, N); 
 
-	vec3 baseColor = vec3(material.r, material.g, material.b);
+	float metallic = material.metallic;
+	float roughness = material.roughness;
 
-	// Diffuse and specular color from material color and metallic factor
+	vec3 F0 = vec3(0.04); 
-	vec3 diffuseColor = baseColor - baseColor * material.metallic;
+	F0 = mix(F0, ALBEDO, metallic);
-	vec3 specularColor = mix(vec3(material.specular), baseColor, material.metallic);
 
-	// Cube map sampling
+	vec3 Lo = vec3(0.0);
-	ivec2 cubedim = textureSize(radianceMap, 0);
+	for(int i = 0; i < uboParams.lights[i].length(); i++) {
-	int numMipLevels = int(log2(max(cubedim.s, cubedim.y)));
+		vec3 L = normalize(uboParams.lights[i].xyz - inWorldPos);
-	float mipLevel = numMipLevels - 1.0 + log2(material.roughness);
+		Lo += specularContribution(L, V, N, F0, metallic, roughness);
-	vec3 radianceSample = pow(textureLod(radianceMap, R, mipLevel).rgb, vec3(2.2f));
+	}   
-	vec3 irradianceSample = pow(texture(irradianceMap, N).rgb, vec3(2.2f));
 	
-	vec3 reflection = EnvBRDFApprox(specularColor, pow(material.roughness, 1.0f), clamp(dot(N, V), 0.0, 1.0));
+	vec2 brdf = texture(samplerBRDFLUT, vec2(max(dot(N, V), 0.0), roughness)).rg;
+	vec3 reflection = prefilteredReflection(R, roughness).rgb;	
+	vec3 irradiance = texture(samplerIrradiance, N).rgb;
 
-	// Combine specular IBL and BRDF
+	// Diffuse based on irradiance
-	vec3 diffuse = diffuseColor * irradianceSample;
+	vec3 diffuse = irradiance * ALBEDO;	
-	vec3 specular = radianceSample * reflection;
+
-	vec3 color = diffuse + specular;
+	vec3 F = F_SchlickR(max(dot(N, V), 0.0), F0, roughness);
+
+	// Specular reflectance
+	vec3 specular = reflection * (F * brdf.x + brdf.y);
+
+	// Ambient part
+	vec3 kD = 1.0 - F;
+	kD *= 1.0 - metallic;	  
+	vec3 ambient = (kD * diffuse + specular);
+	
+	vec3 color = ambient + Lo;
 
 	// Tone mapping
-	color = Uncharted2Tonemap( color * uboShared.exposure );
+	color = Uncharted2Tonemap(color * uboParams.exposure);
 	color = color * (1.0f / Uncharted2Tonemap(vec3(11.2f)));	
 	// Gamma correction
-	color = pow(color, vec3(1.0f / uboShared.gamma));
+	color = pow(color, vec3(1.0f / uboParams.gamma));
 
 	outColor = vec4(color, 1.0);
 }

data/shaders/pbribl/pbribl.vert

@@ -34,5 +34,6 @@ void main()
 	outWorldPos = locPos + pushConsts.objPos;
 	outNormal = mat3(ubo.model) * inNormal;
 	outUV = inUV;
+	outUV.t = 1.0 - inUV.t;
 	gl_Position =  ubo.projection * ubo.view * vec4(outWorldPos, 1.0);
 }

data/shaders/pbribl/skybox.frag

@@ -6,10 +6,11 @@ layout (location = 0) in vec3 inUVW;
 
 layout (location = 0) out vec4 outColor;
 
-layout (binding = 1) uniform UBOShared {
+layout (binding = 1) uniform UBOParams {
+	vec4 lights[4];
 	float exposure;
 	float gamma;
-} uboShared;
+} uboParams;
 
 // From http://filmicworlds.com/blog/filmic-tonemapping-operators/
 vec3 Uncharted2Tonemap(vec3 color)
@@ -26,13 +27,13 @@ vec3 Uncharted2Tonemap(vec3 color)
 
 void main() 
 {
-	vec3 color = pow(texture(samplerEnv, inUVW).rgb, vec3(2.2));
+	vec3 color = texture(samplerEnv, inUVW).rgb;
 
-	color = Uncharted2Tonemap(color * uboShared.exposure);
+	// Tone mapping
-	color = color * (1.0 / Uncharted2Tonemap(vec3(11.2)));
+	color = Uncharted2Tonemap(color * uboParams.exposure);
-	
+	color = color * (1.0f / Uncharted2Tonemap(vec3(11.2f)));	
-	// gamma correction
+	// Gamma correction
-	color = pow(color, vec3(1.0 / uboShared.gamma));
+	color = pow(color, vec3(1.0f / uboParams.gamma));
 	
 	outColor = vec4(color, 1.0);
 }

pbribl/pbribl.cpp

@@ -1,15 +1,15 @@
 /*
 * Vulkan Example - Physical based rendering with image based lighting
 *
-* See http://blog.selfshadow.com/publications/s2013-shading-course/karis/s2013_pbs_epic_notes_v2.pdf
+* Note: Requires the separate (HDR) asset pack (see data/textures/hdr/README.md)
 *
-* Important note: Work in progress (assets missing, may not work or compile, etc.)
+* Copyright (C) 2016-2017 by Sascha Willems - www.saschawillems.de
-*
-* Copyright (C) 2017 by Sascha Willems - www.saschawillems.de
 *
 * This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
 */
 
+// For reference see http://blog.selfshadow.com/publications/s2013-shading-course/karis/s2013_pbs_epic_notes_v2.pdf
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -34,13 +34,14 @@
 #define GRID_DIM 7
 
 struct Material {
-	float roughness;
+	// Set in object rendering loop
-	float metallic;
+	float roughness = 0.0f;
-	float specular;
+	float metallic = 0.0f;
-	float r,g,b;	// Color components as single floats because we use push constants
+	float specular = 0.0f;
+	float r, g, b;
 	std::string name;
 	Material() {};
-	Material(std::string n, glm::vec3 c, float r, float m) : name(n), roughness(r), metallic(m), r(c.r), g(c.g), b(c.b) { specular = 0.8f; };
+	Material(std::string n, glm::vec3 c) : name(n), r(c.r), g(c.g), b(c.b) { };
 };
 
 class VulkanExample : public VulkanExampleBase
@@ -84,7 +85,7 @@ public:
 
 	struct UBOParams {
 		glm::vec4 lights[4];
-		float exposure = 10.0f;
+		float exposure = 2.0f;
 		float gamma = 2.2f;
 	} uboParams;
 
@@ -115,24 +116,25 @@ public:
 		camera.setPerspective(60.0f, (float)width / (float)height, 0.1f, 256.0f);
 		camera.rotationSpeed = 0.25f;
 
-		camera.setRotation({ -22.75f, 180.0f, 0.0f });
+		camera.setRotation({ -3.75f, 180.0f, 0.0f });
-		camera.setPosition({ 1.2, 5.6, 17.0f });
+		camera.setPosition({ 0.55f, 0.85f, 12.0f });
 
 		// Setup some default materials (source: https://seblagarde.wordpress.com/2011/08/17/feeding-a-physical-based-lighting-mode/)
-		materials.push_back(Material("Gold", glm::vec3(1.0f, 0.765557f, 0.336057f), 0.1f, 1.0f));
+		materials.push_back(Material("Gold", glm::vec3(1.0f, 0.765557f, 0.336057f)));
-		materials.push_back(Material("Copper", glm::vec3(0.955008f, 0.637427f, 0.538163f), 0.1f, 1.0f));
+		materials.push_back(Material("Copper", glm::vec3(0.955008f, 0.637427f, 0.538163f)));
-		materials.push_back(Material("Chromium", glm::vec3(0.549585f, 0.556114f, 0.554256f), 0.1f, 1.0f));
+		materials.push_back(Material("Chromium", glm::vec3(0.549585f, 0.556114f, 0.554256f)));
-		materials.push_back(Material("Nickel", glm::vec3(0.659777f, 0.608679f, 0.525649f), 0.1f, 1.0f));
+		materials.push_back(Material("Nickel", glm::vec3(0.659777f, 0.608679f, 0.525649f)));
-		materials.push_back(Material("Titanium", glm::vec3(0.541931f, 0.496791f, 0.449419f), 0.1f, 1.0f));
+		materials.push_back(Material("Titanium", glm::vec3(0.541931f, 0.496791f, 0.449419f)));
-		materials.push_back(Material("Cobalt", glm::vec3(0.662124f, 0.654864f, 0.633732f), 0.1f, 1.0f));
+		materials.push_back(Material("Cobalt", glm::vec3(0.662124f, 0.654864f, 0.633732f)));
-		materials.push_back(Material("Platinum", glm::vec3(0.672411f, 0.637331f, 0.585456f), 0.1f, 1.0f));
+		materials.push_back(Material("Platinum", glm::vec3(0.672411f, 0.637331f, 0.585456f)));
 		// Testing materials
-		materials.push_back(Material("White", glm::vec3(1.0f), 0.1f, 1.0f));
+		materials.push_back(Material("White", glm::vec3(1.0f)));
-		materials.push_back(Material("Red", glm::vec3(1.0f, 0.0f, 0.0f), 0.1f, 1.0f));
+		materials.push_back(Material("Dark", glm::vec3(0.1f)));
-		materials.push_back(Material("Blue", glm::vec3(0.0f, 0.0f, 1.0f), 0.1f, 1.0f));
+		materials.push_back(Material("Black", glm::vec3(0.0f)));
-		materials.push_back(Material("Black", glm::vec3(0.0f), 0.1f, 1.0f));
+		materials.push_back(Material("Red", glm::vec3(1.0f, 0.0f, 0.0f)));
+		materials.push_back(Material("Blue", glm::vec3(0.0f, 0.0f, 1.0f)));
 
-		materialIndex = 7;
+		materialIndex = 9;
 	}
 
 	~VulkanExample()
@@ -385,13 +387,13 @@ public:
 		pipelineCreateInfo.pVertexInputState = &vertexInputState;
 
 		// Skybox pipeline (background cube)
-		shaderStages[0] = loadShader(getAssetPath() + "shaders/pbribl/skybox.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
+		shaderStages[0] = loadShader(ASSET_PATH "shaders/pbribl/skybox.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
-		shaderStages[1] = loadShader(getAssetPath() + "shaders/pbribl/skybox.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
+		shaderStages[1] = loadShader(ASSET_PATH "shaders/pbribl/skybox.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
 		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCreateInfo, nullptr, &pipelines.skybox));
 
 		// PBR pipeline
-		shaderStages[0] = loadShader(getAssetPath() + "shaders/pbribl/pbribl.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
+		shaderStages[0] = loadShader(ASSET_PATH "shaders/pbribl/pbribl.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
-		shaderStages[1] = loadShader(getAssetPath() + "shaders/pbribl/pbribl.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
+		shaderStages[1] = loadShader(ASSET_PATH "shaders/pbribl/pbribl.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
 		// Enable depth test and write
 		depthStencilState.depthWriteEnable = VK_TRUE;
 		depthStencilState.depthTestEnable = VK_TRUE;
@@ -560,8 +562,8 @@ public:
 		pipelineCI.pVertexInputState = &emptyInputState;
 
 		// Look-up-table (from BRDF) pipeline
-		shaderStages[0] = loadShader(getAssetPath() + "shaders/pbribl/genbrdflut.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
+		shaderStages[0] = loadShader(ASSET_PATH "shaders/pbribl/genbrdflut.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
-		shaderStages[1] = loadShader(getAssetPath() + "shaders/pbribl/genbrdflut.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
+		shaderStages[1] = loadShader(ASSET_PATH "shaders/pbribl/genbrdflut.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
 		VkPipeline pipeline;
 		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipeline));
 
@@ -799,8 +801,8 @@ public:
 		struct PushBlock {
 			glm::mat4 mvp;
 			// Sampling deltas
-			float deltaPhi = (2.0f * M_PI) / 180.0f;
+			float deltaPhi = (2.0f * float(M_PI)) / 180.0f;
-			float deltaTheta = (0.5f * M_PI) / 64.0f;
+			float deltaTheta = (0.5f * float(M_PI)) / 64.0f;
 		} pushBlock;
 
 		VkPipelineLayout pipelinelayout;
@@ -847,8 +849,8 @@ public:
 		pipelineCI.pVertexInputState = &vertexInputState;
 		pipelineCI.renderPass = renderpass;
 
-		shaderStages[0] = loadShader(getAssetPath() + "shaders/pbribl/filtercube.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
+		shaderStages[0] = loadShader(ASSET_PATH "shaders/pbribl/filtercube.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
-		shaderStages[1] = loadShader(getAssetPath() + "shaders/pbribl/irradiancecube.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
+		shaderStages[1] = loadShader(ASSET_PATH "shaders/pbribl/irradiancecube.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
 		VkPipeline pipeline;
 		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipeline));
 
@@ -1244,8 +1246,8 @@ public:
 		pipelineCI.pVertexInputState = &vertexInputState;
 		pipelineCI.renderPass = renderpass;
 
-		shaderStages[0] = loadShader(getAssetPath() + "shaders/pbribl/filtercube.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
+		shaderStages[0] = loadShader(ASSET_PATH "shaders/pbribl/filtercube.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
-		shaderStages[1] = loadShader(getAssetPath() + "shaders/pbribl/prefilterenvmap.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
+		shaderStages[1] = loadShader(ASSET_PATH "shaders/pbribl/prefilterenvmap.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
 		VkPipeline pipeline;
 		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipeline));
 
@@ -1573,9 +1575,7 @@ public:
 		textOverlay->addText("\"Button X\" to toggle object", 5.0f, 100.0f, VulkanTextOverlay::alignLeft);
 #else
 		textOverlay->addText("Material: " + materials[materialIndex].name + " (+/-)", 5.0f, 85.0f, VulkanTextOverlay::alignLeft);
-		//textOverlay->addText("Exposure = " + std::to_string(uboParams.exposure) + " (F3/F4)", 5.0f, 100.0f, VulkanTextOverlay::alignLeft);
+		textOverlay->addText("Exposure: " + std::to_string(uboParams.exposure) + " (F3/F4)", 5.0f, 100.0f, VulkanTextOverlay::alignLeft);
-		//textOverlay->addText("\"F2\" to toggle skybox", 5.0f, 85.0f, VulkanTextOverlay::alignLeft);
-		//textOverlay->addText("\"space\" to toggle object", 5.0f, 100.0f, VulkanTextOverlay::alignLeft);
 #endif
 	}
 };