Simple, minimal and header-only scene graph library for NanoRT.
NanoSG itself shoud be compiled with C++-03 compiler, but demo code uses C++11 features.
premake5 gmake
make
premake5 vs2015
Node represents scene graph node. Tansformation node or Mesh(shape) node. Node is interpreted as transformation node when passing nullptr to Node class constructure.
Node can contain multiple children.
Scene contains root nodes and provides the method to find an intersection of nodes.
Following are required in user application.
Current example code assumes mesh is all composed of triangle meshes.
Following method must be implemented for Scene::Traversal.
/// /// Get the geometric normal and the shading normal at `face_idx' th face. /// template<typename T> void GetNormal(T Ng[3], T Ns[3], const unsigned int face_idx, const T u, const T v) const;
Represents intersection(hit) information.
Transformation is done in the following procedure.
M' = parent_xform x local_xform x local_pivot
Scene and Node does not create a copy of asset data(e.g. vertices, indices). Thus user must care about memory management of scene assets in user side.
API is still subject to change.
void Node::SetName(const std::string &name);
Set (unique) name for the node.
void Node::AddChild(const type &child);
Add node as child node.
void Node::SetLocalXform(const T xform[4][4]) {
Set local transformation matrix. Default is identity matrix.
bool Scene::AddNode(const Node<T, M> &node);
Add a node to the scene.
bool Scene::Commit() {
Commit the scene. After adding nodes to the scene or changed transformation matrix, call this Commit before tracing rays. Commit triggers BVH build in each nodes and updates node's transformation matrix.
template<class H> bool Scene::Traverse(nanort::Ray<T> &ray, H *isect, const bool cull_back_face = false) const;
Trace ray into the scene and find an intersection. Returns true when there is an intersection and hit information is stored in isect.