Color gradient ramp for glowing parts of the mesh

data/shaders/radialblur/colorpass.frag

@@ -3,11 +3,22 @@
 #extension GL_ARB_separate_shader_objects : enable
 #extension GL_ARB_shading_language_420pack : enable
 
+layout (binding = 1) uniform sampler2D samplerGradientRamp;
+
 layout (location = 0) in vec3 inColor;
+layout (location = 1) in vec2 inUV;
 
 layout (location = 0) out vec4 outFragColor;
 
 void main() 
 {
-	outFragColor.rgb = inColor;
+	// Use max. color channel value to detect bright glow emitters
+	if ((inColor.r >= 0.9) || (inColor.g >= 0.9) || (inColor.b >= 0.9)) 
+	{
+		outFragColor.rgb = texture(samplerGradientRamp, inUV).rgb;
+	}
+	else
+	{
+		outFragColor.rgb = inColor;
+	}
 }

data/shaders/radialblur/colorpass.vert

@@ -3,16 +3,18 @@
 #extension GL_ARB_separate_shader_objects : enable
 #extension GL_ARB_shading_language_420pack : enable
 
-layout (location = 0) in vec4 inPos;
+layout (location = 0) in vec3 inPos;
 layout (location = 2) in vec3 inColor;
 
 layout (binding = 0) uniform UBO 
 {
 	mat4 projection;
 	mat4 model;
+	float gradientPos;
 } ubo;
 
 layout (location = 0) out vec3 outColor;
+layout (location = 1) out vec2 outUV;
 
 out gl_PerVertex
 {
@@ -22,5 +24,6 @@ out gl_PerVertex
 void main() 
 {
 	outColor = inColor;
-	gl_Position = ubo.projection * ubo.model * inPos;
+	outUV = vec2(ubo.gradientPos, 0.0f);
+	gl_Position = ubo.projection * ubo.model * vec4(inPos, 1.0);
 }

data/shaders/radialblur/phongpass.frag

@@ -3,10 +3,13 @@
 #extension GL_ARB_separate_shader_objects : enable
 #extension GL_ARB_shading_language_420pack : enable
 
+layout (binding = 1) uniform sampler2D samplerGradientRamp;
+
 layout (location = 0) in vec3 inNormal;
 layout (location = 1) in vec3 inColor;
 layout (location = 2) in vec3 inEyePos;
 layout (location = 3) in vec3 inLightVec;
+layout (location = 4) in vec2 inUV;
 
 layout (location = 0) out vec4 outFragColor;
 
@@ -17,7 +20,7 @@ void main()
 	// to detect bright glow emitters
 	if ((inColor.r >= 0.9) || (inColor.g >= 0.9) || (inColor.b >= 0.9)) 
 	{
-		outFragColor.rgb = inColor;
+		outFragColor.rgb = texture(samplerGradientRamp, inUV).rgb;
 	}
 	else
 	{

data/shaders/radialblur/phongpass.vert

@@ -11,12 +11,14 @@ layout (binding = 0) uniform UBO
 {
 	mat4 projection;
 	mat4 model;
+	float gradientPos;
 } ubo;
 
 layout (location = 0) out vec3 outNormal;
 layout (location = 1) out vec3 outColor;
 layout (location = 2) out vec3 outEyePos;
 layout (location = 3) out vec3 outLightVec;
+layout (location = 4) out vec2 outUV;
 
 out gl_PerVertex
 {
@@ -27,6 +29,7 @@ void main()
 {
 	outNormal = inNormal;
 	outColor = inColor;
+	outUV = vec2(ubo.gradientPos, 0.0); 
 	gl_Position = ubo.projection * ubo.model * pos;
 	outEyePos = vec3(ubo.model * pos);
 	vec4 lightPos = vec4(0.0, 0.0, -5.0, 1.0);// * ubo.model;

data/shaders/radialblur/radialblur.frag

@@ -26,7 +26,7 @@ void main()
 	vec4 color = vec4(0.0, 0.0, 0.0, 0.0);
 	UV += radialSize * 0.5 - ubo.radialOrigin;
  
-	#define samples 16
+	#define samples 32
 
 	for (int i = 0; i < samples; i++) 
 	{

radialblur/radialblur.cpp

@@ -47,6 +47,10 @@ public:
 		vkMeshLoader::MeshBuffer quad;
 	} meshes;
 
+	struct {
+		vkTools::VulkanTexture gradient;
+	} textures;
+
 	struct {
 		VkPipelineVertexInputStateCreateInfo inputState;
 		std::vector<VkVertexInputBindingDescription> bindingDescriptions;
@@ -59,18 +63,14 @@ public:
 		vkTools::UniformData fsQuad;
 	} uniformData;
 
-	struct {
+	struct UboVS {
 		glm::mat4 projection;
 		glm::mat4 model;
-	} uboVS;
+		float gradientPos = 0.0f;
+	} uboSceneVS, uboQuadVS;
 
-	struct {
+	struct UboQuadFS {
-		glm::mat4 projection;
+		float radialBlurScale = 0.35f;
-		glm::mat4 model;
-	} uboQuadVS;
-
-	struct {
-		float radialBlurScale = 0.25f;
 		float radialBlurStrength = 0.75f;
 		glm::vec2 radialOrigin = glm::vec2(0.5f, 0.5f);
 	} uboQuadFS;
@@ -165,6 +165,8 @@ public:
 
 		vkFreeCommandBuffers(device, cmdPool, 1, &offscreenPass.commandBuffer);
 		vkDestroySemaphore(device, offscreenPass.semaphore, nullptr);
+
+		textureLoader->destroyTexture(textures.gradient);
 	}
 
 	// Setup the offscreen framebuffer for rendering the blurred scene
@@ -457,6 +459,7 @@ public:
 	void loadAssets()
 	{
 		loadMesh(getAssetPath() + "models/glowsphere.dae", &meshes.example, vertexLayout, 0.05f);
+		textureLoader->loadTexture(getAssetPath() + "textures/particle_gradient_rgba.ktx", VK_FORMAT_R8G8B8A8_UNORM, &textures.gradient, false);
 	}
 
 	// Setup vertices for a single uv-mapped quad
@@ -552,7 +555,7 @@ public:
 		std::vector<VkDescriptorPoolSize> poolSizes =
 		{
 			vkTools::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 4),
-			vkTools::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 2)
+			vkTools::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 6)
 		};
 
 		VkDescriptorPoolCreateInfo descriptorPoolInfo =
@@ -649,7 +652,14 @@ public:
 				descriptorSets.scene,
 				VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER,
 				0,
-				&uniformData.vsQuad.descriptor)
+				&uniformData.vsQuad.descriptor),
+			// Binding 1 : Color gradient sampler
+			vkTools::initializers::writeDescriptorSet(
+				descriptorSets.scene,
+				VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
+				1,
+				&textures.gradient.descriptor)
+
 		};
 		vkUpdateDescriptorSets(device, offScreenWriteDescriptorSets.size(), offScreenWriteDescriptorSets.data(), 0, NULL);
 	}
@@ -765,8 +775,8 @@ public:
 		createBuffer(
 			VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT,
 			VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT,
-			sizeof(uboVS),
+			sizeof(uboSceneVS),
-			&uboVS,
+			&uboSceneVS,
 			&uniformData.vsScene.buffer,
 			&uniformData.vsScene.memory,
 			&uniformData.vsScene.descriptor);
@@ -775,8 +785,8 @@ public:
 		createBuffer(
 			VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT,
 			VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT,
-			sizeof(uboVS),
+			sizeof(uboQuadVS),
-			&uboVS,
+			&uboQuadVS,
 			&uniformData.vsQuad.buffer,
 			&uniformData.vsQuad.memory,
 			&uniformData.vsQuad.descriptor);
@@ -808,6 +818,11 @@ public:
 		uboQuadVS.model = glm::rotate(uboQuadVS.model, glm::radians(timer * 360.0f), glm::vec3(0.0f, 1.0f, 0.0f));
 		uboQuadVS.model = glm::rotate(uboQuadVS.model, glm::radians(rotation.z), glm::vec3(0.0f, 0.0f, 1.0f));
 
+		if (!paused)
+		{
+			uboQuadVS.gradientPos += frameTimer * 0.1f;
+		}
+
 		uint8_t *pData;
 		VK_CHECK_RESULT(vkMapMemory(device, uniformData.vsQuad.memory, 0, sizeof(uboQuadVS), 0, (void **)&pData));
 		memcpy(pData, &uboQuadVS, sizeof(uboQuadVS));
@@ -818,14 +833,19 @@ public:
 	void updateUniformBuffersScreen() 
 	{
 		// Vertex shader
-		uboVS.projection = glm::ortho(0.0f, 1.0f, 0.0f, 1.0f, -1.0f, 1.0f);
+		uboSceneVS.projection = glm::ortho(0.0f, 1.0f, 0.0f, 1.0f, -1.0f, 1.0f);
-		uboVS.model = glm::mat4();
+		uboSceneVS.model = glm::mat4();
 
 		uint8_t *pData;
-		VK_CHECK_RESULT(vkMapMemory(device, uniformData.vsScene.memory, 0, sizeof(uboVS), 0, (void **)&pData));
+		VK_CHECK_RESULT(vkMapMemory(device, uniformData.vsScene.memory, 0, sizeof(uboSceneVS), 0, (void **)&pData));
-		memcpy(pData, &uboVS, sizeof(uboVS));
+		memcpy(pData, &uboSceneVS, sizeof(uboSceneVS));
 		vkUnmapMemory(device, uniformData.vsScene.memory);
 
+		if (!paused)
+		{
+			uboSceneVS.gradientPos += uboQuadVS.gradientPos;
+		}
+
 		// Fragment shader
 		VK_CHECK_RESULT(vkMapMemory(device, uniformData.fsQuad.memory, 0, sizeof(uboQuadFS), 0, (void **)&pData));
 		memcpy(pData, &uboQuadFS, sizeof(uboQuadFS));