初始化后处理阶段屏幕处理器

2026-06-05 14:35:42 +08:00
commit 263bb68686
23 changed files with 515 additions and 0 deletions
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+using System.Collections.Generic;
+using UnityEngine;
+using UnityEngine.Rendering;
+using UnityEngine.Rendering.Universal;
+
+#if UNITY_2022_1_OR_NEWER // urp 13
+namespace XericLibrary.PostProcess
+{
+    // 定义数据结构，用来存储展平后的 SubMesh 信息
+    [System.Serializable]
+    public struct SubMeshDrawData
+    {
+        public Mesh mesh;
+        public Matrix4x4 matrix;
+        public int subMeshIndex;
+        public int uniqueMatID;
+    }
+
+    public class GeoLayerPickerRenderPassFeature : ScriptableRendererFeature
+    {
+        
+        // 在 Feature 外部类中，添加 Inspector 面板需要的配置参数
+        [Header("拾取设置")]
+        public Material pickMaterial;
+        public MeshFilter[] geoMeshes;
+        public Vector2Int pickRTSize = new Vector2Int(64, 64);
+
+        // 内部持有的资源
+        private RenderTexture m_PickRT;
+        private List<SubMeshDrawData> m_DrawList = new List<SubMeshDrawData>();
+
+        class GeoLayerPickerRenderPass : ScriptableRenderPass
+        {
+            public Material passMaterial;
+            public RenderTexture passRT;
+            public List<SubMeshDrawData> passDrawList;
+            
+            private int m_MatIDProperty = Shader.PropertyToID("_MatID");
+            
+            public override void OnCameraSetup(CommandBuffer cmd, ref RenderingData renderingData)
+            {
+                // 在 URP 中，必须在这里告诉管线我们要渲染到哪张 RT 上
+                if (passRT != null)
+                {
+                    ConfigureTarget(new RenderTargetIdentifier(passRT));
+                    ConfigureClear(ClearFlag.All, Color.clear);
+                }
+            }
+
+            public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData)
+            {
+                // 安全检查
+                if (passMaterial == null || passRT == null || passDrawList == null || passDrawList.Count == 0) 
+                    return;
+
+                // 从对象池获取 CommandBuffer (性能更好)
+                CommandBuffer cmd = CommandBufferPool.Get("GeoLayerPickBuffer");
+
+                // 在 URP 13 中，绝对不能在 Execute 里用 cmd.SetRenderTarget()。必须重写 OnCameraSetup，使用 ConfigureTarget() 告诉 URP 这个 Pass 的输出目标是你创建的 m_PickRT。
+                // 设置视口为 RT 的尺寸 (64x64)
+                cmd.SetViewport(new Rect(0, 0, passRT.width, passRT.height));
+
+                // 【核心】遍历绘制每一个 SubMesh
+                for (int i = 0; i < passDrawList.Count; i++)
+                {
+                    var data = passDrawList[i];
+                    cmd.SetGlobalInt(m_MatIDProperty, data.uniqueMatID);
+                    // 注意第四个参数 submeshIndex，这是多材质插槽的关键
+                    cmd.DrawMesh(data.mesh, data.matrix, passMaterial, data.subMeshIndex);
+                }
+
+                // 提交命令给 GPU 执行
+                context.ExecuteCommandBuffer(cmd);
+                CommandBufferPool.Release(cmd);
+            }
+
+            public override void OnCameraCleanup(CommandBuffer cmd)
+            {
+            }
+        }
+
+        GeoLayerPickerRenderPass m_ScriptablePass;
+
+        public override void Create()
+        {
+            m_ScriptablePass = new GeoLayerPickerRenderPass();
+
+            m_ScriptablePass.renderPassEvent = RenderPassEvent.AfterRenderingOpaques;
+
+            // 【步骤 4】在 Create 中初始化 RT，并展平 SubMesh 数据
+            if (m_PickRT != null) m_PickRT.Release();
+            m_PickRT = new RenderTexture(pickRTSize.x, pickRTSize.y, 0, RenderTextureFormat.ARGB32);
+            m_PickRT.Create();
+
+            RebuildDrawList();
+        }
+
+        
+        // 提供一个公开方法，方便运行时动态刷新网格列表
+        public void RebuildDrawList()
+        {
+            m_DrawList.Clear();
+            if (geoMeshes == null) 
+                return;
+            
+            int globalIDCounter = 1; // ID 从 1 开始，0 留给背景
+            foreach (var mf in geoMeshes)
+            {
+                if (mf == null || mf.sharedMesh == null) continue;
+
+                // 遍历网格的每一个材质插槽 (SubMesh)
+                for (int sub = 0; sub < mf.sharedMesh.subMeshCount; sub++)
+                {
+                    m_DrawList.Add(new SubMeshDrawData
+                    {
+                        mesh = mf.sharedMesh,
+                        matrix = mf.transform.localToWorldMatrix,
+                        subMeshIndex = sub,
+                        uniqueMatID = globalIDCounter++
+                    });
+                }
+            }
+        }
+
+        public override void AddRenderPasses(ScriptableRenderer renderer, ref RenderingData renderingData)
+        {
+            // 将外部数据传递给内部的 Pass，并注入管线
+            if (m_ScriptablePass != null)
+            {
+                m_ScriptablePass.passMaterial = pickMaterial;
+                m_ScriptablePass.passRT = m_PickRT;
+                m_ScriptablePass.passDrawList = m_DrawList;
+                
+                renderer.EnqueuePass(m_ScriptablePass);
+            }
+        }
+        
+        
+        // 暴露 RT 给外部读取像素用
+        public RenderTexture GetPickRT() => m_PickRT;
+    }
+}
+#endif