Question

我正在为计算机图形学建立一个Octree。尝试使用以下代码构建树：

void Accel::build() {
    Octree *m_octree = new Octree(depth);
    std::vector<uint32_t> indices(triangleCount);
    for (uint32_t i = 0; i < triangleCount; ++i) {
        indices[i] = i;
    }
    m_octree->root = m_octree->octreeBuild(m_bbox, indices, m_mesh);
}

树和树节点类如下：

Octree.h

class Octree {
public:
        uint32_t totalNodes = 0;
        uint32_t maxDepth = 0;
        uint32_t totalDepth = 0;
        std::vector<OctreeNode *> octreeVector;
        OctreeNode *root;

        Octree();
        Octree(uint32_t d);
        ~Octree();

        OctreeNode *octreeBuild(BoundingBox3f boundingBox, std::vector<uint32_t> indices, Mesh* mesh);
};

Octree.cpp

Octree::Octree(){}
Octree::Octree(uint32_t d): maxDepth(d) {}
Octree::~Octree(){
}

OctreeNode *Octree::octreeBuild(BoundingBox3f boundingBox, std::vector<uint32_t> indices, Mesh* mesh) {
    if (indices.empty()) {
        OctreeNode *node = nullptr;
        octreeVector.push_back(node);
        return node;
    }

    if (indices.size() <= 10 || totalDepth == maxDepth) {
        OctreeNode *node = new OctreeNode(indices, boundingBox, true);
        octreeVector.push_back(node);
        totalNodes += 1;
        return node;
    }


    if (totalDepth < maxDepth){
        std::vector<uint32_t>  nodeArray[8]; // Eight vector to store child node indices

        BoundingBox3f boxArray[8] = {
            boundingBox, boundingBox, boundingBox, boundingBox, boundingBox, boundingBox, boundingBox, boundingBox
    }; // Eight bounding box, one for each child node

        for (uint32_t i = 0; i < 8; ++i) { // Seperate bounding box
            Point3f corner = boundingBox.getCorner(i);
            Point3f center = boundingBox.getCenter();

            Point3f minPoint = Point3f(std::min(corner.x(), center.x()), std::min(corner.y(), center.y()), std::min(corner.z(), center.z()));
            Point3f maxPoint = Point3f(std::max(corner.x(), center.x()), std::max(corner.y(), center.y()), std::max(corner.z(), center.z()));

            boxArray[i] = BoundingBox3f(minPoint, maxPoint);
        }

        for (uint32_t i = 0; i < static_cast<uint32_t>(indices.size()); i++) { // Check overlapping, store indices to cooresponding vector
            BoundingBox3f triangleBox = mesh->getBoundingBox(i);
            for (uint32_t j = 0; j < 8; ++j) {
                if (boxArray[j].overlaps(triangleBox) && boxArray[j].contains(triangleBox.getCenter())) {
                    nodeArray[j].push_back(i);
                    break;
                }
            }
        }

        OctreeNode *node = new OctreeNode(indices, boundingBox, false); // Build the new node with children
        octreeVector.push_back(node);
        if (octreeVector.size() == 1) {
            root = node;
        }
        totalDepth += 1;
        for (uint32_t i = 0; i < 8; ++i) {
            node->child[i] = octreeBuild(boxArray[i], nodeArray[i], mesh);
            totalNodes += 1;
        }
        return node;
    }

    return nullptr;
};

我设法构建程序，并且Octree :: build顺利通过，没有错误消息。但是在尝试搜索树根之后，出现了EXC_BAD_ACCESS错误。看来我八叉树的根已经消失了。我是C ++的新手，不确定是否是因为算法或我用C ++编程的方式是错误的。感谢您的任何建议！

树根节点的C ++ EXC_BAD_ACCESS

0 个答案: