Added starfield backdrop to instancing example

data/shaders/instancing/instancing.frag

@@ -20,7 +20,7 @@ void main()
 	vec3 L = normalize(inLightVec);
 	vec3 V = normalize(inViewVec);
 	vec3 R = reflect(-L, N);
-	vec3 diffuse = max(dot(N, L), 0.0) * inColor;
+	vec3 diffuse = max(dot(N, L), 0.1) * inColor;
 	vec3 specular = (dot(N,L) > 0.0) ? pow(max(dot(R, V), 0.0), 16.0) * vec3(0.75) * color.r : vec3(0.0);
 	outFragColor = vec4(diffuse * color.rgb + specular, 1.0);		
 }

data/shaders/instancing/starsphere.frag

@@ -0,0 +1,34 @@
+#version 450
+
+layout (location = 0) in vec3 inUVW;
+
+layout (location = 0) out vec4 outFragColor;
+
+#define HASHSCALE3 vec3(443.897, 441.423, 437.195)
+#define STARFREQUENCY 0.01
+
+// Hash function by Dave Hoskins (https://www.shadertoy.com/view/4djSRW)
+float hash33(vec3 p3)
+{
+	p3 = fract(p3 * HASHSCALE3);
+	p3 += dot(p3, p3.yxz+vec3(19.19));
+	return fract((p3.x + p3.y)*p3.z + (p3.x+p3.z)*p3.y + (p3.y+p3.z)*p3.x);
+}
+
+vec3 starField(vec3 pos)
+{
+	vec3 color = vec3(0.0);
+	float threshhold = (1.0 - STARFREQUENCY);
+	float rnd = hash33(pos);
+	if (rnd >= threshhold)
+	{
+		float starCol = pow((rnd - threshhold) / (1.0 - threshhold), 16.0);
+		color += vec3(starCol);
+	}	
+	return color;
+}
+
+void main() 
+{
+	outFragColor = vec4(starField(inUVW), 1.0);
+}

data/shaders/instancing/starsphere.vert

@@ -0,0 +1,9 @@
+#version 450
+
+layout (location = 0) out vec3 outUVW;
+
+void main() 
+{
+	outUVW = vec3((gl_VertexIndex << 1) & 2, gl_VertexIndex & 2, gl_VertexIndex & 2);
+	gl_Position = vec4(outUVW.st * 2.0f - 1.0f, 0.0f, 1.0f);
+}

instancing/instancing.cpp

@@ -81,6 +81,7 @@ public:
 	struct {
 		VkPipeline instancedRocks;
 		VkPipeline planet;
+		VkPipeline starfield;
 	} pipelines;
 
 	VkDescriptorSetLayout descriptorSetLayout;
@@ -89,7 +90,6 @@ public:
 		VkDescriptorSet planet;
 	} descriptorSets;
 
-
 	VulkanExample() : VulkanExampleBase(ENABLE_VALIDATION)
 	{
 		title = "Vulkan Example - Instanced mesh rendering";
@@ -105,6 +105,7 @@ public:
 	{
 		vkDestroyPipeline(device, pipelines.instancedRocks, nullptr);
 		vkDestroyPipeline(device, pipelines.planet, nullptr);
+		vkDestroyPipeline(device, pipelines.starfield, nullptr);
 		vkDestroyPipelineLayout(device, pipelineLayout, nullptr);
 		vkDestroyDescriptorSetLayout(device, descriptorSetLayout, nullptr);
 		vkDestroyBuffer(device, instanceBuffer.buffer, nullptr);
@@ -148,6 +149,11 @@ public:
 
 			VkDeviceSize offsets[1] = { 0 };
 
+			// Star field
+			vkCmdBindDescriptorSets(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayout, 0, 1, &descriptorSets.planet, 0, NULL);
+			vkCmdBindPipeline(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelines.starfield);
+			vkCmdDraw(drawCmdBuffers[i], 4, 1, 0, 0);
+
 			// Planet
 			vkCmdBindDescriptorSets(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayout, 0, 1, &descriptorSets.planet, 0, NULL);
 			vkCmdBindPipeline(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelines.planet);
@@ -378,6 +384,16 @@ public:
 		inputState.vertexBindingDescriptionCount = 1;
 		inputState.vertexAttributeDescriptionCount = 4;
 		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCreateInfo, nullptr, &pipelines.planet));
+
+		// Star field pipeline
+		rasterizationState.cullMode = VK_CULL_MODE_NONE;
+		depthStencilState.depthWriteEnable = VK_FALSE;
+		shaderStages[0] = loadShader(getAssetPath() + "shaders/instancing/starfield.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
+		shaderStages[1] = loadShader(getAssetPath() + "shaders/instancing/starfield.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
+		// Vertices are generated in the vertex shader
+		inputState.vertexBindingDescriptionCount = 0;
+		inputState.vertexAttributeDescriptionCount = 0;
+		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCreateInfo, nullptr, &pipelines.starfield));
 	}
 
 	float rnd(float range)

instancing/instancing.vcxproj

@@ -26,6 +26,8 @@
     <None Include="..\data\shaders\instancing\instancing.vert" />
     <None Include="..\data\shaders\instancing\planet.frag" />
     <None Include="..\data\shaders\instancing\planet.vert" />
+    <None Include="..\data\shaders\instancing\starsphere.frag" />
+    <None Include="..\data\shaders\instancing\starsphere.vert" />
   </ItemGroup>
   <PropertyGroup Label="Globals">
     <ProjectGuid>{CF2E27EC-5A81-412A-A3E2-E6EB5C8B66E3}</ProjectGuid>

instancing/instancing.vcxproj.filters

@@ -55,5 +55,11 @@
     <None Include="..\data\shaders\instancing\planet.vert">
       <Filter>Shaders</Filter>
     </None>
+    <None Include="..\data\shaders\instancing\starsphere.frag">
+      <Filter>Shaders</Filter>
+    </None>
+    <None Include="..\data\shaders\instancing\starsphere.vert">
+      <Filter>Shaders</Filter>
+    </None>
   </ItemGroup>
 </Project>

vulkanExamples.sln

@@ -127,6 +127,7 @@ EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{9E815C67-731B-4559-938E-23CD771F0860}"
 	ProjectSection(SolutionItems) = preProject
 		CMakeLists.txt = CMakeLists.txt
+		README.md = README.md
 	EndProjectSection
 EndProject
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "screenshot", "screenshot\screenshot.vcxproj", "{AD1DAD4D-A753-4A78-88E2-B4DCE15D482F}"