110 lines
3.5 KiB
C
110 lines
3.5 KiB
C
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/*
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This file is part of Nori, a simple educational ray tracer
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Copyright (c) 2015 by Wenzel Jakob
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Nori is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License Version 3
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as published by the Free Software Foundation.
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Nori is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#pragma once
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#include <nori/mesh.h>
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NORI_NAMESPACE_BEGIN
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static constexpr uint32_t MAX_TRIANGLES_PER_NODE = 15;
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static constexpr uint32_t MAX_RECURSION_DEPTH = 10;
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static constexpr uint32_t MAX_NUM_MESHES = 32;
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/**
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* \brief Acceleration data structure for ray intersection queries
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*
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* The current implementation falls back to a brute force loop
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* through the geometry.
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*/
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class Accel {
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struct Node {
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uint32_t num_triangles = 0;
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BoundingBox3f bbox;
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Node* next = nullptr;
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Node* child = nullptr;
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uint32_t* triangle_indices = nullptr;
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uint32_t* mesh_indices = nullptr;
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~Node() {
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delete[] triangle_indices;
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delete[] mesh_indices;
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delete next;
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delete child;
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}
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};
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public:
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~Accel() { delete m_root; }
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/**
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* \brief Register a triangle mesh for inclusion in the acceleration
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* data structure
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*
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* This function can only be used before \ref build() is called
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*/
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void addMesh(Mesh *mesh);
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/// Build the acceleration data structure (currently a no-op)
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void build();
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/// Return an axis-aligned box that bounds the scene
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const BoundingBox3f &getBoundingBox() const { return m_bbox; }
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/**
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* \brief Intersect a ray against all triangles stored in the scene and
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* return detailed intersection information
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*
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* \param ray
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* A 3-dimensional ray data structure with minimum/maximum extent
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* information
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*
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* \param its
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* A detailed intersection record, which will be filled by the
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* intersection query
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*
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* \param shadowRay
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* \c true if this is a shadow ray query, i.e. a query that only aims to
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* find out whether the ray is blocked or not without returning detailed
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* intersection information.
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*
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* \return \c true if an intersection was found
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*/
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bool rayIntersect(const Ray3f &ray, Intersection &its, bool shadowRay) const;
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private:
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Node* buildRecursive(const BoundingBox3f& bbox, std::vector<uint32_t>& triangle_indices,
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std::vector<uint32_t>& mesh_indices, uint32_t recursion_depth);
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bool traverseRecursive(const Node& node, Ray3f &ray, Intersection &its, bool shadowRay, uint32_t& hit_idx) const;
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static void subdivideBBox(const BoundingBox3f& parent, BoundingBox3f* bboxes);
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Mesh* m_meshes[MAX_NUM_MESHES]; ///< Meshes (up to MAX_NUM_MESHES meshes)
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BoundingBox3f m_bbox; ///< Bounding box of the entire scene
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Node* m_root = nullptr; ///< Root node of Octree
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uint32_t m_num_meshes = 0; ///< number of meshes in accel
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// only statistics
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uint32_t m_num_nonempty_leaf_nodes = 0;
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uint32_t m_num_leaf_nodes = 0;
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uint32_t m_num_nodes = 0;
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uint32_t m_recursion_depth = 0;
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uint32_t m_num_triangles_saved = 0;
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};
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NORI_NAMESPACE_END
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