uniform buffer for grass shader parameters

beaumanvienna · Jun 23, 2024 · d4eb502 · d4eb502
1 parent a318c5e
commit d4eb502
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Showing 11 changed files with 87 additions and 32 deletions.
diff --git a/application/lucre/models/assets b/application/lucre/models/assets
diff --git a/application/lucre/sceneDescriptions/terrain.json b/application/lucre/sceneDescriptions/terrain.json
@@ -343,7 +343,7 @@
                         ],
                         "translation":
                         [
-                            -0.745493, 2.37433, -0.536219
+                            -0.745493, 2.329, -0.536219
                         ]
                     }
                 }

diff --git a/application/lucre/terrainDescriptions/lucre island.json b/application/lucre/terrainDescriptions/lucre island.json
@@ -27,6 +27,8 @@
             [
                 4.37885, -1.14346, 59.3405
             ]
-        }
+        }, 
+        "scaleXZ": 5.0,
+        "scaleY": 7.0
     }
 }
diff --git a/engine/platform/Vulkan/VKrenderer.cpp b/engine/platform/Vulkan/VKrenderer.cpp
@@ -154,6 +154,7 @@ namespace GfxRenderEngine
                 .AddBinding(0, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, VK_SHADER_STAGE_VERTEX_BIT) // shader data for instances
                 .AddBinding(1, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, VK_SHADER_STAGE_VERTEX_BIT) // dummy
                 .AddBinding(2, VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, VK_SHADER_STAGE_VERTEX_BIT) // shader data for height map
+                .AddBinding(3, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, VK_SHADER_STAGE_VERTEX_BIT) // shader parameters
                 .Build();
 
         std::unique_ptr<VK_DescriptorSetLayout> instanceDescriptorSetLayout =

diff --git a/engine/platform/Vulkan/VKresourceDescriptor.cpp b/engine/platform/Vulkan/VKresourceDescriptor.cpp
@@ -35,6 +35,7 @@ namespace GfxRenderEngine
         auto& instBuffer = buffers[Resources::INSTANCE_BUFFER_INDEX];
         auto& skelBuffer = buffers[Resources::SKELETAL_ANIMATION_BUFFER_INDEX];
         auto& hBuffer = buffers[Resources::HEIGHTMAP];
+        auto& mPurposeBuffer = buffers[Resources::MULTI_PURPOSE_BUFFER];
 
         // instance buffer
         std::shared_ptr<Buffer>& instanceUbo = instBuffer ? instBuffer : gDummyBuffer;
@@ -51,35 +52,48 @@ namespace GfxRenderEngine
         VK_Buffer* heightmapBuffer = static_cast<VK_Buffer*>(heightmapUbo.get());
         VkDescriptorBufferInfo heightmapBufferInfo = heightmapBuffer->DescriptorInfo();
 
+        // multi purpose
+        std::shared_ptr<Buffer>& multiPurposeUbo = mPurposeBuffer ? mPurposeBuffer : gDummyBuffer;
+        VK_Buffer* multiPurposeBuffer = static_cast<VK_Buffer*>(multiPurposeUbo.get());
+        VkDescriptorBufferInfo multiPurposeBufferInfo = multiPurposeBuffer->DescriptorInfo();
+
         {
             VK_DescriptorSetLayout::Builder builder{};
-            if (instBuffer || skelBuffer || hBuffer)
+            if (instBuffer || skelBuffer || hBuffer || mPurposeBuffer)
             {
                 builder.AddBinding(0, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, VK_SHADER_STAGE_VERTEX_BIT);
             }
-            if (skelBuffer || hBuffer)
+            if (skelBuffer || hBuffer || mPurposeBuffer)
             {
                 builder.AddBinding(1, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, VK_SHADER_STAGE_VERTEX_BIT);
             }
-            if (hBuffer)
+            if (hBuffer || mPurposeBuffer)
             {
                 builder.AddBinding(2, VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, VK_SHADER_STAGE_VERTEX_BIT);
             }
+            if (mPurposeBuffer)
+            {
+                builder.AddBinding(3, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, VK_SHADER_STAGE_VERTEX_BIT);
+            }
             std::unique_ptr<VK_DescriptorSetLayout> localDescriptorSetLayout = builder.Build();
 
             VK_DescriptorWriter descriptorWriter(*localDescriptorSetLayout, *VK_Renderer::m_DescriptorPool);
-            if (instBuffer || skelBuffer || hBuffer)
+            if (instBuffer || skelBuffer || hBuffer || mPurposeBuffer)
             {
                 descriptorWriter.WriteBuffer(0, instanceBufferInfo);
             }
-            if (skelBuffer || hBuffer)
+            if (skelBuffer || hBuffer || mPurposeBuffer)
             {
                 descriptorWriter.WriteBuffer(1, skeletalAnimationBufferInfo);
             }
-            if (hBuffer)
+            if (hBuffer || mPurposeBuffer)
             {
                 descriptorWriter.WriteBuffer(2, heightmapBufferInfo);
             }
+            if (mPurposeBuffer)
+            {
+                descriptorWriter.WriteBuffer(3, multiPurposeBufferInfo);
+            }
             descriptorWriter.Build(m_DescriptorSet);
         }
 

diff --git a/engine/platform/Vulkan/shaders/grass.vert b/engine/platform/Vulkan/shaders/grass.vert
@@ -61,19 +61,22 @@ layout(set = 0, binding = 0) uniform GlobalUniformBuffer
     int m_NumberOfActiveDirectionalLights;
 } ubo;
 
+layout(set = 2, binding = 3) uniform ParameterBuffer
+{
+    int m_Width;
+    int m_Height; // not used, 
+    float m_ScaleXZ;
+    float m_ScaleY;
+} parameters;
+
 layout(set = 2, binding = 0) uniform InstanceUniformBuffer
 {
     InstanceData m_InstanceData;
 } baseTransform;
 
-#define WIDTH 512 // row
-#define HEIGHT 375 // col
-#define NUM_HEIGHT_VALUES WIDTH*HEIGHT // 192000
-#define INSTANCE_COUNT NUM_HEIGHT_VALUES
-
 layout(set = 2, binding = 2) readonly buffer HeightMap
 {
-    int m_HeightMapData[INSTANCE_COUNT]; 
+    int m_HeightMapData[1]; // actual array size is larger than 1
 } heightMap;
 
 layout(location = 0) out vec3 fragPosition;
@@ -89,14 +92,14 @@ void main()
 
     int index = gl_InstanceIndex;
     float hgt = heightMap.m_HeightMapData[index];
-    float row = floor(index / WIDTH);
-    float col = floor((index - WIDTH * row));
+    float row = floor(index / parameters.m_Width);
+    float col = floor((index - parameters.m_Width * row));
 
     float theta = sin(hgt+gl_InstanceIndex); // random
     float s = sin(theta); // sine
     float c = cos(theta); // cosine
-    float sclXZ = 5.0;
-    float sclY = 5.0;
+    float sclXZ = parameters.m_ScaleXZ;
+    float sclY = parameters.m_ScaleY;
 
     mat4 translation = mat4
     (
@@ -138,7 +141,6 @@ void main()
                                 1.0 )  // fourth column
     );
 
-
     mat4 scale = mat4
     (
         vec4(  sclXZ,

diff --git a/engine/platform/Vulkan/shaders/pbrSA.vert b/engine/platform/Vulkan/shaders/pbrSA.vert
@@ -111,7 +111,7 @@ void main()
     gl_Position = ubo.m_Projection * ubo.m_View * positionWorld;
     fragPosition = positionWorld.xyz;
 
-    mat3 normalMatrix = transpose(inverse(mat3(instanceNormalMatrix) * mat3(jointTransform)));
+    mat3 normalMatrix = transpose(inverse(mat3(modelMatrix) * mat3(jointTransform)));
     fragNormal = normalize(normalMatrix * normal);
     fragTangent = normalize(normalMatrix * tangent);
 

diff --git a/engine/renderer/builder/terrainBuilder.cpp b/engine/renderer/builder/terrainBuilder.cpp
@@ -293,19 +293,34 @@ namespace GfxRenderEngine
                 uint heightMapSize = heightMap.Size();
                 Resources::ResourceBuffers resourceBuffers;
                 {
-                    // unforunately, need to copy one buffer into another (glsl does not support uint8_t by default)
-                    std::vector<int> bufferData(heightMapSize);
-                    for (uint index = 0; index < heightMapSize; ++index)
+                    { // unforunately, need to copy one buffer into another (glsl does not support uint8_t by default)
+                        std::vector<int> bufferData(heightMapSize);
+                        for (uint index = 0; index < heightMapSize; ++index)
+                        {
+                            bufferData[index] = heightMap[index];
+                        }
+                        int bufferSize = heightMapSize * sizeof(int); // in bytes
+                        auto& ubo = resourceBuffers[Resources::HEIGHTMAP];
+                        ubo = Buffer::Create(bufferSize, Buffer::BufferUsage::STORAGE_BUFFER_VISIBLE_TO_CPU);
+                        ubo->MapBuffer();
+                        // update ubo
+                        ubo->WriteToBuffer(bufferData.data());
+                        ubo->Flush();
+                    }
+
                     {
-                        bufferData[index] = heightMap[index];
+                        Terrain::GrassParameters grassParameters{.m_Width = heightMap.Width(),
+                                                                 .m_Height = heightMap.Height(),
+                                                                 .m_ScaleXZ = grassSpec.m_ScaleXZ,
+                                                                 .m_ScaleY = grassSpec.m_ScaleY};
+                        int bufferSize = sizeof(Terrain::GrassParameters);
+                        auto& ubo = resourceBuffers[Resources::MULTI_PURPOSE_BUFFER];
+                        ubo = Buffer::Create(bufferSize, Buffer::BufferUsage::UNIFORM_BUFFER_VISIBLE_TO_CPU);
+                        ubo->MapBuffer();
+                        // update ubo
+                        ubo->WriteToBuffer(&grassParameters);
+                        ubo->Flush();
                     }
-                    int bufferSize = heightMapSize * sizeof(int); // in bytes
-                    auto& ubo = resourceBuffers[Resources::HEIGHTMAP];
-                    ubo = Buffer::Create(bufferSize, Buffer::BufferUsage::STORAGE_BUFFER_VISIBLE_TO_CPU);
-                    resourceBuffers[Resources::HEIGHTMAP]->MapBuffer();
-                    // update ubo
-                    ubo->WriteToBuffer(bufferData.data());
-                    ubo->Flush();
 
                     FastgltfBuilder builder(grassSpec.m_FilepathGrassModel, scene, &resourceBuffers);
                     builder.Load(1 /*1 instance in scene graph (grass has the instance count in the tag)*/);

diff --git a/engine/scene/resource.h b/engine/scene/resource.h
@@ -39,6 +39,7 @@ namespace GfxRenderEngine
             INSTANCE_BUFFER_INDEX = 0,
             SKELETAL_ANIMATION_BUFFER_INDEX,
             HEIGHTMAP,
+            MULTI_PURPOSE_BUFFER,
             NUM_BUFFERS
         };
 

diff --git a/engine/scene/terrain.h b/engine/scene/terrain.h
@@ -39,6 +39,14 @@ namespace GfxRenderEngine
             Instance(entt::entity entity) : m_Entity{entity} {}
         };
 
+        struct GrassParameters
+        {
+            int m_Width;
+            int m_Height; // not used,
+            float m_ScaleXZ;
+            float m_ScaleY;
+        };
+
         struct TerrainDescription
         {
             std::string m_Filename;
@@ -54,6 +62,8 @@ namespace GfxRenderEngine
             glm::vec3 m_Translation{};
             glm::vec3 m_Rotation{};
             glm::vec3 m_Scale{};
+            float m_ScaleXZ{1.0f};
+            float m_ScaleY{1.0f};
         };
 
         struct TerrainSpec

diff --git a/engine/scene/terrainLoaderDeserializeJSON.cpp b/engine/scene/terrainLoaderDeserializeJSON.cpp
@@ -182,6 +182,16 @@ namespace GfxRenderEngine
                 ondemand::object transformJSON = grassAttribute.value().get_object();
                 ParseTransform(transformJSON);
             }
+            else if (grassAttributeKey == "scaleXZ")
+            {
+                CORE_ASSERT((grassAttribute.value().type() == ondemand::json_type::number), "type must be number");
+                grassSpec.m_ScaleXZ = grassAttribute.value().get_double();
+            }
+            else if (grassAttributeKey == "scaleY")
+            {
+                CORE_ASSERT((grassAttribute.value().type() == ondemand::json_type::number), "type must be number");
+                grassSpec.m_ScaleY = grassAttribute.value().get_double();
+            }
             else
             {
                 LOG_CORE_CRITICAL("unrecognized grass attribute");