unsigned int BVHAccel::BuildArray(BVHAccelTreeNode *node, unsigned int offset) {
// Build array by recursively traversing the tree depth-first
while (node) {
BVHAccelArrayNode *p = &bvhTree[offset];
p->bbox = node->bbox;
p->primitive = node->primitive;
offset = BuildArray(node->leftChild, offset + 1);
p->skipIndex = offset;
node = node->rightSibling;
}
return offset;
}
void BVHAccel::Init(const std::deque<Mesh *> &meshes, const unsigned int totalVertexCount,
const unsigned int totalTriangleCount) {
assert (!initialized);
preprocessedMesh = TriangleMesh::Merge(totalVertexCount, totalTriangleCount,
meshes, &preprocessedMeshIDs, &preprocessedMeshTriangleIDs);
assert (preprocessedMesh->GetTotalVertexCount() == totalVertexCount);
assert (preprocessedMesh->GetTotalTriangleCount() == totalTriangleCount);
LR_LOG(ctx, "Total vertices memory usage: " << totalVertexCount * sizeof(Point) / 1024 << "Kbytes");
LR_LOG(ctx, "Total triangles memory usage: " << totalTriangleCount * sizeof(Triangle) / 1024 << "Kbytes");
const Point *v = preprocessedMesh->GetVertices();
const Triangle *p = preprocessedMesh->GetTriangles();
std::vector<BVHAccelTreeNode *> bvList;
for (unsigned int i = 0; i < totalTriangleCount; ++i) {
BVHAccelTreeNode *ptr = new BVHAccelTreeNode();
ptr->bbox = p[i].WorldBound(v);
// NOTE - Ratow - Expand bbox a little to make sure rays collide
ptr->bbox.Expand(MachineEpsilon::E(ptr->bbox));
ptr->primitive = i;
ptr->leftChild = NULL;
ptr->rightSibling = NULL;
bvList.push_back(ptr);
}
LR_LOG(ctx, "Building Bounding Volume Hierarchy, primitives: " << totalTriangleCount);
nNodes = 0;
BVHAccelTreeNode *rootNode = BuildHierarchy(bvList, 0, bvList.size(), 2);
LR_LOG(ctx, "Pre-processing Bounding Volume Hierarchy, total nodes: " << nNodes);
bvhTree = new BVHAccelArrayNode[nNodes];
BuildArray(rootNode, 0);
FreeHierarchy(rootNode);
LR_LOG(ctx, "Total BVH memory usage: " << nNodes * sizeof(BVHAccelArrayNode) / 1024 << "Kbytes");
LR_LOG(ctx, "Finished building Bounding Volume Hierarchy array");
initialized = true;
}
void BuildInput(void) {
BuildArray();
BuildInitial();
}