[{“source”:{“position”:0,“lines”:[”

添加图片注释，不超过 140 字（可选）

省略启发式AABB构建过程…

SDF形状实现

基类：

[ExecuteInEditMode]"]},"target":{"position":0,"lines":["添加图片注释，不超过 140 字（可选）省略启发式AABB构建过程....SDF形状实现基类：[ExecuteInEditMode]"]},"type":"CHANGE"},{"source":{"position":22,"lines":["  }s_shapeComponents：存放场景中所有启用的 RayMarchedShape 实例。s_tree：对应的 AABB 树结构，用于快速做空间剔除和射线相交测试。s_sdfShapes：每帧根据组件列表生成的 SdfShape 数组，降低运行时的内存分配和 GC 频率，逻辑上不是必须。private int m_shapeIndex = -1;"]},"target":{"position":22,"lines":["  }s_shapeComponents：存放场景中所有启用的 RayMarchedShape 实例。s_tree：对应的 AABB 树结构，用于快速做空间剔除和射线相交测试。s_sdfShapes：每帧根据组件列表生成的 SdfShape 数组，降低运行时的内存分配和 GC 频率，逻辑上不是必须。private int m_shapeIndex = -1;"]},"type":"CHANGE"},{"source":{"position":46,"lines":["}OnEnable：每当一个带 RayMarchedShape 的 GameObject 激活时，就把它加入 s_shapeComponents，并在 s_tree 中开辟一个 proxy，用它来跟踪该物体的包围盒（Bounds）。OnDisable：移除列表和 BVH proxy。同样保证列表紧凑，无“空洞”。public static int FillAabbTree(ComputeBuffer buffer, float aabbTightenRadius = 0.0f)"]},"target":{"position":46,"lines":["}OnEnable：每当一个带 RayMarchedShape 的 GameObject 激活时，就把它加入 s_shapeComponents，并在 s_tree 中开辟一个 proxy，用它来跟踪该物体的包围盒（Bounds）。OnDisable：移除列表和 BVH proxy。同样保证列表紧凑，无“空洞”。public static int FillAabbTree(ComputeBuffer buffer, float aabbTightenRadius = 0.0f)"]},"type":"CHANGE"},{"source":{"position":57,"lines":["}SyncBounds：把每个组件最新的 Bounds（由子类 override）写入对应的 proxy。Fill：让 AABB 树重建内部节点，并把树的数据打平写入到 GPU 用的 ComputeBuffer。返回值 root 是根节点在数组中的下标，也会传给 GPU Shader，用来做递归遍历。SDF形状：[StructLayout(LayoutKind.Sequential, Pack = 0)]"]},"target":{"position":57,"lines":["}SyncBounds：把每个组件最新的 Bounds（由子类 override）写入对应的 proxy。Fill：让 AABB 树重建内部节点，并把树的数据打平写入到 GPU 用的 ComputeBuffer。返回值 root 是根节点在数组中的下标，也会传给 GPU Shader，用来做递归遍历。球类（继承类）：[ExecuteInEditMode]","public class RayMarchedSphere : RayMarchedShape","{","  public float Radius = 0.5f;","","  protected override SdfShape Shape","  {","    get","    {","      return SdfShape.Sphere(transform.position, Radius);","    }","  }","","  public override Aabb Bounds","  {","    get","    {","      return ","        new Aabb","        (","          transform.position - Radius * Vector3.one, ","          transform.position + Radius * Vector3.one","        );","    }","  }","","  protected override void OnValidate()","  {","    base.OnValidate();","","    Radius = Mathf.Max(0.0f, Radius);","  }","}球的AABB包围盒的求法很简单，符合直觉SDF形状：[StructLayout(LayoutKind.Sequential, Pack = 0)]"]},"type":"CHANGE"},{"source":{"position":152,"lines":["}球类（继承类）：[ExecuteInEditMode]","public class RayMarchedSphere : RayMarchedShape","{","  public float Radius = 0.5f;","","  protected override SdfShape Shape","  {","    get","    {","      return SdfShape.Sphere(transform.position, Radius);","    }","  }","","  public override Aabb Bounds","  {","    get","    {","      return ","        new Aabb","        (","          transform.position - Radius * Vector3.one, ","          transform.position + Radius * Vector3.one","        );","    }","  }","","  protected override void OnValidate()","  {","    base.OnValidate();","","    Radius = Mathf.Max(0.0f, Radius);","  }","}球的AABB包围盒的求法很简单，符合直觉RayMarching 后处理 ComputeShader// cs"]},"target":{"position":184,"lines":["}RayMarching 后处理 ComputeShader// cs"]},"type":"CHANGE"},{"source":{"position":195,"lines":["var camera = window ? window.camera : null;可以获取Scene视图的相机，还真是万物皆可组件，Scene上也有Camera组件求交  // gather shapes around ray by casting it against AABB tree"]},"target":{"position":195,"lines":["var camera = window ? window.camera : null;可以获取Scene视图的相机，还真是万物皆可组件，Scene上也有Camera组件求交  // gather shapes around ray by casting it against AABB tree"]},"type":"CHANGE"},{"source":{"position":201,"lines":["  );数量：numNearShapes 这是一个计数器，初始为 0。 索引列表：数组 aiNearShape（长度上限 kMaxShapesPerRay）用来存放「这条射线可能会命中的」那些 SDF 形状在全局 aSdfShape 数组里的 索引（shapeIndex）。数组下标范围是 0~numNearShapes-1，每次发现一个叶子 AABB 被射线击中，就把它对应的 shapeIndex push 进去。March Ray//对 numNearShapes 个候选形状做距离评估"]},"target":{"position":201,"lines":["  );数量：numNearShapes 这是一个计数器，初始为 0。 索引列表：数组 aiNearShape（长度上限 kMaxShapesPerRay）用来存放「这条射线可能会命中的」那些 SDF 形状在全局 aSdfShape 数组里的 索引（shapeIndex）。数组下标范围是 0~numNearShapes-1，每次发现一个叶子 AABB 被射线击中，就把它对应的 shapeIndex push 进去。March Ray//对 numNearShapes 个候选形状做距离评估"]},"type":"CHANGE"},{"source":{"position":285,"lines":["}这段代码没有严谨地考虑穿过的情况，也就是两个Step之间距离都小于hitDst的情况，但场景里都是球体，并没有厚度小于hitDst的平面。看完这个代码我才知道原来SDF在渲染中的作用就是计算法线。用立方体的四个对顶角计算，4 个点正好能提供三个自由度的梯度信息（∂x,∂y,∂z）加上一个整体偏移。添加图片注释，不超过 140 字（可选）Lerp 平滑// 平滑并集（smooth union）"]},"target":{"position":285,"lines":["}这段代码没有严谨地考虑穿过的情况，也就是两个Step之间距离都小于hitDst的情况，但场景里都是球体，并没有厚度小于hitDst的平面。看完这个代码我才知道原来SDF在渲染中的作用就是计算法线。用立方体的四个对顶角计算，4 个点正好能提供三个自由度的梯度信息（∂x,∂y,∂z）加上一个整体偏移。添加图片注释，不超过 140 字（可选）Lerp 平滑// 平滑并集（smooth union）"]},"type":"CHANGE"}]