aabb

.gitignore

@@ -2,4 +2,5 @@
 .cache
 /target
 /scenes
-.vscode
+.vscode
+/examples

CMakeLists.txt

@@ -28,6 +28,8 @@ add_executable(Moer
  src/CoreLayer/Math/Transform.cpp
 
  src/FunctionLayer/Acceleration/EmbreeBVH.cpp
+ src/FunctionLayer/Acceleration/AABB.cpp
+
  src/FunctionLayer/Integrator/NormalIntegrator.cpp
  src/FunctionLayer/Integrator/DirectIntegrator.cpp
  src/FunctionLayer/Integrator/WhittedIntegrator.cpp

README.md

@@ -30,6 +30,8 @@ Moer-lite的框架基于Moer主干：https://github.com/NJUCG/Moer .
 - 2023-3-2 添加了进度条，whitted-style积分器，镜面材质以及一个新场景cornell-box。
 - 2023-3-10 
  - 修改了Cube.cpp 28、29行bug（之前代码正确性不影响，但是逻辑不对）
+ - 修改了Triangle.cpp中的bug（之前当mesh文件不存在法线和纹理信息时会发生段错误）
+ - 对AABB进行封装（见Shape::getAABB）
 
 ## TODO
 - 对mesh和sphere实现表面采样（目前只有parallelogram可以配置为面光源）

src/FunctionLayer/Acceleration/AABB.cpp

@@ -0,0 +1,52 @@
+#include "AABB.h"
+
+Point3f minP(const Point3f &p1, const Point3f &p2) {
+ return Point3f{std::min(p1[0], p2[0]), std::min(p1[1], p2[1]),
+ std::min(p1[2], p2[2])};
+}
+
+Point3f maxP(const Point3f &p1, const Point3f &p2) {
+ return Point3f{std::max(p1[0], p2[0]), std::max(p1[1], p2[1]),
+ std::max(p1[2], p2[2])};
+}
+
+AABB AABB::Union(const AABB &other) const {
+ Point3f min = minP(other.pMin, pMin), max = maxP(other.pMax, pMax);
+ return AABB{min, max};
+}
+
+void AABB::Expand(const AABB &other) {
+ pMin = minP(pMin, other.pMin);
+ pMax = maxP(pMax, other.pMax);
+}
+
+AABB AABB::Union(const Point3f &other) const {
+ Point3f min = minP(other, pMin), max = maxP(other, pMax);
+ return AABB{min, max};
+}
+
+void AABB::Expand(const Point3f &other) {
+ pMin = minP(pMin, other);
+ pMax = maxP(pMax, other);
+}
+
+bool AABB::rayIntersect(const Ray &ray, float *tMin, float *tMax) const {
+ float tNear = ray.tNear, tFar = ray.tFar;
+ for (int i = 0; i < 3; ++i) {
+ float invDir = 1.f / ray.direction[i];
+ float t0 = (pMin[i] - ray.origin[i]) * invDir,
+ t1 = (pMax[i] - ray.origin[i]) * invDir;
+ if (t0 > t1)
+ std::swap(t0, t1);
+ tNear = std::max(tNear, t0);
+ tFar = std::min(tFar, t1);
+
+ if (tNear > tFar)
+ return false;
+ }
+ if (tMin)
+ *tMin = tNear;
+ if (tMax)
+ *tMax = tFar;
+ return true;
+}

src/FunctionLayer/Acceleration/AABB.h

@@ -0,0 +1,27 @@
+#pragma once
+#include <CoreLayer/Math/Math.h>
+#include <FunctionLayer/Ray/Ray.h>
+// Axis-aligned Bounding box，即AABB
+class AABB {
+public:
+ AABB() {
+ pMin = Point3f{FLT_MAX, FLT_MAX, FLT_MAX};
+ pMax = Point3f{-FLT_MAX, -FLT_MAX, -FLT_MAX};
+ }
+
+ AABB(const Point3f &_pMin, const Point3f &_pMax) : pMin(_pMin), pMax(_pMax) {}
+
+ AABB Union(const AABB &other) const;
+
+ void Expand(const AABB &other);
+
+ AABB Union(const Point3f &other) const;
+
+ void Expand(const Point3f &other);
+
+ bool rayIntersect(const Ray &ray, float *tMin = nullptr,
+ float *tMax = nullptr) const;
+
+public:
+ Point3f pMin, pMax;
+};

src/FunctionLayer/Shape/Cube.cpp

@@ -9,7 +9,6 @@ Cube::Cube(const Json &json) : Shape(json) {
  boxMax = Point3f{1.f, 1.f, 1.f};
 
  // 构建AABB
- pMin = pMax = transform.toWorld(boxMin);
  for (int i = 0; i < 8; ++i) {
  Point3f p;
  p[0] = (i & 0b100) ? boxMax[0] : boxMin[0];
@@ -18,8 +17,7 @@ Cube::Cube(const Json &json) : Shape(json) {
  p = transform.toWorld(p);
 
  for (int j = 0; j < 3; ++j) {
- pMin[j] = std::min(pMin[j], p[j]);
- pMax[j] = std::max(pMax[j], p[j]);
+ boundingBox.Expand(p);
  }
  }
 

src/FunctionLayer/Shape/Parallelogram.cpp

@@ -15,12 +15,9 @@ Parallelogram::Parallelogram(const Json &json) : Shape(json) {
  vertices[1] = vertices[0] + edge0;
  vertices[2] = vertices[1] + edge1;
  vertices[3] = vertices[0] + edge1;
- pMin = pMax = vertices[0]; // 初始化
- for (int dim = 0; dim < 3; ++dim) {
- for (int i = 1; i < 4; ++i) {
- pMin[dim] = std::min(pMin[dim], vertices[i][dim]);
- pMax[dim] = std::max(pMax[dim], vertices[i][dim]);
- }
+
+ for (int i = 0; i < 4; ++i) {
+ boundingBox.Expand(vertices[i]);
  }
 }
 

src/FunctionLayer/Shape/Shape.cpp

@@ -28,8 +28,6 @@ Shape::Shape(const Json &json) {
  }
 }
 
-std::pair<Point3f, Point3f> Shape::getAABB() const { return {pMin, pMax}; }
-
 void UserShapeBound(const RTCBoundsFunctionArguments *args) {
  Shape *shape = static_cast<Shape *>(args->geometryUserPtr);
  auto [pMin, pMax] = shape->getAABB();

src/FunctionLayer/Shape/Shape.h

@@ -1,5 +1,6 @@
 #pragma once
 #include "Intersection.h"
+#include <FunctionLayer/Acceleration/AABB.h>
 #include <FunctionLayer/Ray/Ray.h>
 #include <ResourceLayer/JsonUtil.h>
 #include <embree3/rtcore.h>
@@ -16,8 +17,7 @@ class Shape : public Transformable {
 
  virtual RTCGeometry getEmbreeGeometry(RTCDevice device) const;
 
- // TODO 对AABB做一个封装
- std::pair<Point3f, Point3f> getAABB() const;
+ AABB getAABB() const { return boundingBox; }
 
  virtual bool rayIntersectShape(const Ray &ray, float *distance, int *primID,
  float *u, float *v) const = 0;
@@ -37,5 +37,5 @@ class Shape : public Transformable {
  std::shared_ptr<Material> material;
 
 protected:
- Point3f pMin, pMax; // AABB包围盒，构建时初始化
+ AABB boundingBox;
 };

src/FunctionLayer/Shape/Sphere.cpp

@@ -6,8 +6,7 @@ Sphere::Sphere(const Json &json) : Shape(json) {
  radius = fetchRequired<float>(json, "radius");
 
  center = transform.toWorld(center);
- pMin = center - Vector3f(radius);
- pMax = center + Vector3f(radius);
+ boundingBox = AABB(center - Vector3f(radius), center + Vector3f(radius));
 }
 
 bool Sphere::rayIntersectShape(const Ray &ray, float *distance, int *primID,

src/FunctionLayer/Shape/Triangle.cpp

@@ -53,16 +53,27 @@ void Triangle::fillIntersection(float distance, int primID, float u, float v,
  w * pw[1] + u * pu[1] + v * pv[1],
  w * pw[2] + u * pu[2] + v * pv[2]};
  //* 计算法线
- Vector3f nw = transform.toWorld(mesh->normalBuffer[faceInfo[0].normalIndex]),
- nu = transform.toWorld(mesh->normalBuffer[faceInfo[1].normalIndex]),
- nv = transform.toWorld(mesh->normalBuffer[faceInfo[2].normalIndex]);
- intersection->normal = normalize(w * nw + u * nu + v * nv);
+ if (mesh->normalBuffer.size() != 0) {
+ Vector3f nw =
+ transform.toWorld(mesh->normalBuffer[faceInfo[0].normalIndex]),
+ nu =
+ transform.toWorld(mesh->normalBuffer[faceInfo[1].normalIndex]),
+ nv =
+ transform.toWorld(mesh->normalBuffer[faceInfo[2].normalIndex]);
+ intersection->normal = normalize(w * nw + u * nu + v * nv);
+ } else {
+ intersection->normal = normalize(cross(pu - pw, pv - pw));
+ }
 
  //* 计算纹理坐标
- Vector2f tw = mesh->texcodBuffer[faceInfo[0].texcodIndex],
- tu = mesh->texcodBuffer[faceInfo[1].texcodIndex],
- tv = mesh->texcodBuffer[faceInfo[2].texcodIndex];
- intersection->texCoord = w * tw + u * tu + v * tv;
+ if (mesh->texcodBuffer.size() != 0) {
+ Vector2f tw = mesh->texcodBuffer[faceInfo[0].texcodIndex],
+ tu = mesh->texcodBuffer[faceInfo[1].texcodIndex],
+ tv = mesh->texcodBuffer[faceInfo[2].texcodIndex];
+ intersection->texCoord = w * tw + u * tu + v * tv;
+ } else {
+ intersection->texCoord = Vector2f{.0f, .0f};
+ }
 
  // TODO 计算交点的切线和副切线
  Vector3f tangent{1.f, 0.f, .0f};