908 lines
36 KiB
C#
908 lines
36 KiB
C#
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/*
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Copyright (c) 2023 Omar Duarte
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Unauthorized copying of this file, via any medium is strictly prohibited.
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Modified by Omar Duarte, 2020.
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This file incorporates work covered by the following copyright and
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permission notice:
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Copyright (c) 2014, Nition, BSD licence. All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright notice, this
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list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright notice,
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this list of conditions and the following disclaimer in the documentation
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and/or other materials provided with the distribution.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
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FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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using UnityEngine;
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namespace PluginMaster
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{
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// A node in a BoundsOctree
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public class BoundsOctreeNode<T>
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{
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// Centre of this node
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public Vector3 Center { get; private set; }
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// Length of this node if it has a looseness of 1.0
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public float BaseLength { get; private set; }
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// Looseness value for this node
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float looseness;
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// Minimum size for a node in this octree
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float minSize;
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// Actual length of sides, taking the looseness value into account
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float adjLength;
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// Bounding box that represents this node
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Bounds bounds = default(Bounds);
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// Objects in this node
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readonly System.Collections.Generic.List<OctreeObject> objects = new System.Collections.Generic.List<OctreeObject>();
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// Child nodes, if any
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BoundsOctreeNode<T>[] children = null;
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bool HasChildren { get { return children != null; } }
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// Bounds of potential children to this node. These are actual size (with looseness taken into account), not base size
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Bounds[] childBounds;
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// If there are already NUM_OBJECTS_ALLOWED in a node, we split it into children
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// A generally good number seems to be something around 8-15
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const int NUM_OBJECTS_ALLOWED = 8;
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// An object in the octree
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struct OctreeObject
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{
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public T Obj;
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public Bounds Bounds;
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}
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/// <summary>
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/// Constructor.
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/// </summary>
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/// <param name="baseLengthVal">Length of this node, not taking looseness into account.</param>
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/// <param name="minSizeVal">Minimum size of nodes in this octree.</param>
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/// <param name="loosenessVal">Multiplier for baseLengthVal to get the actual size.</param>
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/// <param name="centerVal">Centre position of this node.</param>
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public BoundsOctreeNode(float baseLengthVal, float minSizeVal, float loosenessVal, Vector3 centerVal)
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{
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SetValues(baseLengthVal, minSizeVal, loosenessVal, centerVal);
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}
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// #### PUBLIC METHODS ####
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/// <summary>
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/// Add an object.
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/// </summary>
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/// <param name="obj">Object to add.</param>
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/// <param name="objBounds">3D bounding box around the object.</param>
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/// <returns>True if the object fits entirely within this node.</returns>
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public bool Add(T obj, Bounds objBounds)
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{
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if (!Encapsulates(bounds, objBounds))
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{
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return false;
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}
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SubAdd(obj, objBounds);
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return true;
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}
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/// <summary>
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/// Remove an object. Makes the assumption that the object only exists once in the tree.
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/// </summary>
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/// <param name="obj">Object to remove.</param>
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/// <returns>True if the object was removed successfully.</returns>
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public bool Remove(T obj)
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{
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bool removed = false;
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for (int i = 0; i < objects.Count; i++)
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{
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if (objects[i].Obj.Equals(obj))
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{
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removed = objects.Remove(objects[i]);
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break;
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}
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}
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if (!removed && children != null)
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{
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for (int i = 0; i < 8; i++)
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{
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removed = children[i].Remove(obj);
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if (removed) break;
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}
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}
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if (removed && children != null)
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{
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// Check if we should merge nodes now that we've removed an item
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if (ShouldMerge())
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{
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Merge();
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}
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}
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return removed;
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}
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/// <summary>
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/// Removes the specified object at the given position. Makes the assumption that the object only exists once in the tree.
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/// </summary>
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/// <param name="obj">Object to remove.</param>
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/// <param name="objBounds">3D bounding box around the object.</param>
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/// <returns>True if the object was removed successfully.</returns>
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public bool Remove(T obj, Bounds objBounds)
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{
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if (!Encapsulates(bounds, objBounds))
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{
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return false;
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}
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return SubRemove(obj, objBounds);
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}
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/// <summary>
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/// Check if the specified bounds intersect with anything in the tree. See also: GetColliding.
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/// </summary>
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/// <param name="checkBounds">Bounds to check.</param>
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/// <returns>True if there was a collision.</returns>
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public bool IsColliding(ref Bounds checkBounds)
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{
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// Are the input bounds at least partially in this node?
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if (!bounds.Intersects(checkBounds))
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{
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return false;
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}
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// Check against any objects in this node
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for (int i = 0; i < objects.Count; i++)
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{
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if (objects[i].Bounds.Intersects(checkBounds))
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{
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return true;
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}
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}
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// Check children
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if (children != null)
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{
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for (int i = 0; i < 8; i++)
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{
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if (children[i].IsColliding(ref checkBounds))
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{
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return true;
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}
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}
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}
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return false;
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}
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/// <summary>
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/// Check if the specified ray intersects with anything in the tree. See also: GetColliding.
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/// </summary>
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/// <param name="checkRay">Ray to check.</param>
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/// <param name="maxDistance">Distance to check.</param>
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/// <returns>True if there was a collision.</returns>
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public bool IsColliding(ref Ray checkRay, float maxDistance = float.PositiveInfinity)
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{
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// Is the input ray at least partially in this node?
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float distance;
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if (!bounds.IntersectRay(checkRay, out distance) || distance > maxDistance)
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{
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return false;
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}
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// Check against any objects in this node
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for (int i = 0; i < objects.Count; i++)
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{
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if (objects[i].Bounds.IntersectRay(checkRay, out distance) && distance <= maxDistance)
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{
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return true;
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}
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}
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// Check children
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if (children != null)
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{
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for (int i = 0; i < 8; i++)
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{
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if (children[i].IsColliding(ref checkRay, maxDistance))
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{
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return true;
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}
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}
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}
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return false;
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}
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/// <summary>
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/// Returns an array of objects that intersect with the specified bounds, if any. Otherwise returns an empty array. See also: IsColliding.
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/// </summary>
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/// <param name="checkBounds">Bounds to check. Passing by ref as it improves performance with structs.</param>
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/// <param name="result">List result.</param>
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/// <returns>Objects that intersect with the specified bounds.</returns>
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public void GetColliding(ref Bounds checkBounds, System.Collections.Generic.List<T> result)
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{
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// Are the input bounds at least partially in this node?
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if (!bounds.Intersects(checkBounds))
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{
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return;
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}
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// Check against any objects in this node
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for (int i = 0; i < objects.Count; i++)
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{
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if (objects[i].Bounds.Intersects(checkBounds))
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{
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result.Add(objects[i].Obj);
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}
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}
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// Check children
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if (children != null)
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{
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for (int i = 0; i < 8; i++)
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{
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children[i].GetColliding(ref checkBounds, result);
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}
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}
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}
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/// <summary>
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/// Returns an array of objects that intersect with the specified ray, if any. Otherwise returns an empty array. See also: IsColliding.
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/// </summary>
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/// <param name="checkRay">Ray to check. Passing by ref as it improves performance with structs.</param>
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/// <param name="maxDistance">Distance to check.</param>
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/// <param name="result">List result.</param>
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/// <returns>Objects that intersect with the specified ray.</returns>
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public void GetColliding(ref Ray checkRay, System.Collections.Generic.List<T> result, float maxDistance = float.PositiveInfinity)
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{
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float distance;
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// Is the input ray at least partially in this node?
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if (!bounds.IntersectRay(checkRay, out distance) || distance > maxDistance)
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{
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return;
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}
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// Check against any objects in this node
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for (int i = 0; i < objects.Count; i++)
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{
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if (objects[i].Bounds.IntersectRay(checkRay, out distance) && distance <= maxDistance)
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{
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result.Add(objects[i].Obj);
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}
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}
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// Check children
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if (children != null)
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{
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for (int i = 0; i < 8; i++)
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{
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children[i].GetColliding(ref checkRay, result, maxDistance);
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}
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}
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}
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public void GetWithinFrustum(Plane[] planes, System.Collections.Generic.List<T> result)
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{
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// Is the input node inside the frustum?
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if (!GeometryUtility.TestPlanesAABB(planes, bounds))
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{
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return;
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}
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// Check against any objects in this node
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for (int i = 0; i < objects.Count; i++)
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{
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if (GeometryUtility.TestPlanesAABB(planes, objects[i].Bounds))
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{
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result.Add(objects[i].Obj);
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}
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}
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// Check children
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if (children != null)
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{
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for (int i = 0; i < 8; i++)
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{
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children[i].GetWithinFrustum(planes, result);
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}
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}
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}
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/// <summary>
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/// Set the 8 children of this octree.
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/// </summary>
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/// <param name="childOctrees">The 8 new child nodes.</param>
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public void SetChildren(BoundsOctreeNode<T>[] childOctrees)
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{
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if (childOctrees.Length != 8)
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{
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Debug.LogError("Child octree array must be length 8. Was length: " + childOctrees.Length);
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return;
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}
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children = childOctrees;
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}
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public Bounds GetBounds()
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{
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return bounds;
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}
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/// <summary>
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/// We can shrink the octree if:
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/// - This node is >= double minLength in length
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/// - All objects in the root node are within one octant
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/// - This node doesn't have children, or does but 7/8 children are empty
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/// We can also shrink it if there are no objects left at all!
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/// </summary>
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/// <param name="minLength">Minimum dimensions of a node in this octree.</param>
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/// <returns>The new root, or the existing one if we didn't shrink.</returns>
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public BoundsOctreeNode<T> ShrinkIfPossible(float minLength)
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{
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if (BaseLength < (2 * minLength))
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{
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return this;
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}
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if (objects.Count == 0 && (children == null || children.Length == 0))
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{
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return this;
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}
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// Check objects in root
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int bestFit = -1;
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for (int i = 0; i < objects.Count; i++)
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{
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OctreeObject curObj = objects[i];
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|
|
int newBestFit = BestFitChild(curObj.Bounds.center);
|
|||
|
|
if (i == 0 || newBestFit == bestFit)
|
|||
|
|
{
|
|||
|
|
// In same octant as the other(s). Does it fit completely inside that octant?
|
|||
|
|
if (Encapsulates(childBounds[newBestFit], curObj.Bounds))
|
|||
|
|
{
|
|||
|
|
if (bestFit < 0)
|
|||
|
|
{
|
|||
|
|
bestFit = newBestFit;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
else
|
|||
|
|
{
|
|||
|
|
// Nope, so we can't reduce. Otherwise we continue
|
|||
|
|
return this;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
else
|
|||
|
|
{
|
|||
|
|
return this; // Can't reduce - objects fit in different octants
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// Check objects in children if there are any
|
|||
|
|
if (children != null)
|
|||
|
|
{
|
|||
|
|
bool childHadContent = false;
|
|||
|
|
for (int i = 0; i < children.Length; i++)
|
|||
|
|
{
|
|||
|
|
if (children[i].HasAnyObjects())
|
|||
|
|
{
|
|||
|
|
if (childHadContent)
|
|||
|
|
{
|
|||
|
|
return this; // Can't shrink - another child had content already
|
|||
|
|
}
|
|||
|
|
if (bestFit >= 0 && bestFit != i)
|
|||
|
|
{
|
|||
|
|
return this; // Can't reduce - objects in root are in a different octant to objects in child
|
|||
|
|
}
|
|||
|
|
childHadContent = true;
|
|||
|
|
bestFit = i;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// Can reduce
|
|||
|
|
if (children == null)
|
|||
|
|
{
|
|||
|
|
// We don't have any children, so just shrink this node to the new size
|
|||
|
|
// We already know that everything will still fit in it
|
|||
|
|
SetValues(BaseLength / 2, minSize, looseness, childBounds[bestFit].center);
|
|||
|
|
return this;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// No objects in entire octree
|
|||
|
|
if (bestFit == -1)
|
|||
|
|
{
|
|||
|
|
return this;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// We have children. Use the appropriate child as the new root node
|
|||
|
|
return children[bestFit];
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Find which child node this object would be most likely to fit in.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="objBounds">The object's bounds.</param>
|
|||
|
|
/// <returns>One of the eight child octants.</returns>
|
|||
|
|
public int BestFitChild(Vector3 objBoundsCenter)
|
|||
|
|
{
|
|||
|
|
return (objBoundsCenter.x <= Center.x ? 0 : 1) + (objBoundsCenter.y >= Center.y ? 0 : 4) + (objBoundsCenter.z <= Center.z ? 0 : 2);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Checks if this node or anything below it has something in it.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <returns>True if this node or any of its children, grandchildren etc have something in them</returns>
|
|||
|
|
public bool HasAnyObjects()
|
|||
|
|
{
|
|||
|
|
if (objects.Count > 0) return true;
|
|||
|
|
|
|||
|
|
if (children != null)
|
|||
|
|
{
|
|||
|
|
for (int i = 0; i < 8; i++)
|
|||
|
|
{
|
|||
|
|
if (children[i].HasAnyObjects()) return true;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
return false;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// #### PRIVATE METHODS ####
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Set values for this node.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="baseLengthVal">Length of this node, not taking looseness into account.</param>
|
|||
|
|
/// <param name="minSizeVal">Minimum size of nodes in this octree.</param>
|
|||
|
|
/// <param name="loosenessVal">Multiplier for baseLengthVal to get the actual size.</param>
|
|||
|
|
/// <param name="centerVal">Centre position of this node.</param>
|
|||
|
|
void SetValues(float baseLengthVal, float minSizeVal, float loosenessVal, Vector3 centerVal)
|
|||
|
|
{
|
|||
|
|
BaseLength = baseLengthVal;
|
|||
|
|
minSize = minSizeVal;
|
|||
|
|
looseness = loosenessVal;
|
|||
|
|
Center = centerVal;
|
|||
|
|
adjLength = looseness * baseLengthVal;
|
|||
|
|
|
|||
|
|
// Create the bounding box.
|
|||
|
|
Vector3 size = new Vector3(adjLength, adjLength, adjLength);
|
|||
|
|
bounds = new Bounds(Center, size);
|
|||
|
|
|
|||
|
|
float quarter = BaseLength / 4f;
|
|||
|
|
float childActualLength = (BaseLength / 2) * looseness;
|
|||
|
|
Vector3 childActualSize = new Vector3(childActualLength, childActualLength, childActualLength);
|
|||
|
|
childBounds = new Bounds[8];
|
|||
|
|
childBounds[0] = new Bounds(Center + new Vector3(-quarter, quarter, -quarter), childActualSize);
|
|||
|
|
childBounds[1] = new Bounds(Center + new Vector3(quarter, quarter, -quarter), childActualSize);
|
|||
|
|
childBounds[2] = new Bounds(Center + new Vector3(-quarter, quarter, quarter), childActualSize);
|
|||
|
|
childBounds[3] = new Bounds(Center + new Vector3(quarter, quarter, quarter), childActualSize);
|
|||
|
|
childBounds[4] = new Bounds(Center + new Vector3(-quarter, -quarter, -quarter), childActualSize);
|
|||
|
|
childBounds[5] = new Bounds(Center + new Vector3(quarter, -quarter, -quarter), childActualSize);
|
|||
|
|
childBounds[6] = new Bounds(Center + new Vector3(-quarter, -quarter, quarter), childActualSize);
|
|||
|
|
childBounds[7] = new Bounds(Center + new Vector3(quarter, -quarter, quarter), childActualSize);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Private counterpart to the public Add method.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="obj">Object to add.</param>
|
|||
|
|
/// <param name="objBounds">3D bounding box around the object.</param>
|
|||
|
|
void SubAdd(T obj, Bounds objBounds)
|
|||
|
|
{
|
|||
|
|
// We know it fits at this level if we've got this far
|
|||
|
|
|
|||
|
|
// We always put things in the deepest possible child
|
|||
|
|
// So we can skip some checks if there are children aleady
|
|||
|
|
if (!HasChildren)
|
|||
|
|
{
|
|||
|
|
// Just add if few objects are here, or children would be below min size
|
|||
|
|
if (objects.Count < NUM_OBJECTS_ALLOWED || (BaseLength / 2) < minSize)
|
|||
|
|
{
|
|||
|
|
OctreeObject newObj = new OctreeObject { Obj = obj, Bounds = objBounds };
|
|||
|
|
objects.Add(newObj);
|
|||
|
|
return; // We're done. No children yet
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// Fits at this level, but we can go deeper. Would it fit there?
|
|||
|
|
// Create the 8 children
|
|||
|
|
int bestFitChild;
|
|||
|
|
if (children == null)
|
|||
|
|
{
|
|||
|
|
Split();
|
|||
|
|
if (children == null)
|
|||
|
|
{
|
|||
|
|
Debug.LogError("Child creation failed for an unknown reason. Early exit.");
|
|||
|
|
return;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// Now that we have the new children, see if this node's existing objects would fit there
|
|||
|
|
for (int i = objects.Count - 1; i >= 0; i--)
|
|||
|
|
{
|
|||
|
|
OctreeObject existingObj = objects[i];
|
|||
|
|
// Find which child the object is closest to based on where the
|
|||
|
|
// object's center is located in relation to the octree's center
|
|||
|
|
bestFitChild = BestFitChild(existingObj.Bounds.center);
|
|||
|
|
// Does it fit?
|
|||
|
|
if (Encapsulates(children[bestFitChild].bounds, existingObj.Bounds))
|
|||
|
|
{
|
|||
|
|
children[bestFitChild].SubAdd(existingObj.Obj, existingObj.Bounds); // Go a level deeper
|
|||
|
|
objects.Remove(existingObj); // Remove from here
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// Handle the new object we're adding now
|
|||
|
|
int bestFit = BestFitChild(objBounds.center);
|
|||
|
|
if (Encapsulates(children[bestFit].bounds, objBounds))
|
|||
|
|
{
|
|||
|
|
children[bestFit].SubAdd(obj, objBounds);
|
|||
|
|
}
|
|||
|
|
else
|
|||
|
|
{
|
|||
|
|
// Didn't fit in a child. We'll have to it to this node instead
|
|||
|
|
OctreeObject newObj = new OctreeObject { Obj = obj, Bounds = objBounds };
|
|||
|
|
objects.Add(newObj);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Private counterpart to the public <see cref="Remove(T, Bounds)"/> method.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="obj">Object to remove.</param>
|
|||
|
|
/// <param name="objBounds">3D bounding box around the object.</param>
|
|||
|
|
/// <returns>True if the object was removed successfully.</returns>
|
|||
|
|
bool SubRemove(T obj, Bounds objBounds)
|
|||
|
|
{
|
|||
|
|
bool removed = false;
|
|||
|
|
|
|||
|
|
for (int i = 0; i < objects.Count; i++)
|
|||
|
|
{
|
|||
|
|
if (objects[i].Obj.Equals(obj))
|
|||
|
|
{
|
|||
|
|
removed = objects.Remove(objects[i]);
|
|||
|
|
break;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
if (!removed && children != null)
|
|||
|
|
{
|
|||
|
|
int bestFitChild = BestFitChild(objBounds.center);
|
|||
|
|
removed = children[bestFitChild].SubRemove(obj, objBounds);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
if (removed && children != null)
|
|||
|
|
{
|
|||
|
|
// Check if we should merge nodes now that we've removed an item
|
|||
|
|
if (ShouldMerge())
|
|||
|
|
{
|
|||
|
|
Merge();
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
return removed;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Splits the octree into eight children.
|
|||
|
|
/// </summary>
|
|||
|
|
void Split()
|
|||
|
|
{
|
|||
|
|
float quarter = BaseLength / 4f;
|
|||
|
|
float newLength = BaseLength / 2;
|
|||
|
|
children = new BoundsOctreeNode<T>[8];
|
|||
|
|
children[0] = new BoundsOctreeNode<T>(newLength, minSize, looseness, Center + new Vector3(-quarter, quarter, -quarter));
|
|||
|
|
children[1] = new BoundsOctreeNode<T>(newLength, minSize, looseness, Center + new Vector3(quarter, quarter, -quarter));
|
|||
|
|
children[2] = new BoundsOctreeNode<T>(newLength, minSize, looseness, Center + new Vector3(-quarter, quarter, quarter));
|
|||
|
|
children[3] = new BoundsOctreeNode<T>(newLength, minSize, looseness, Center + new Vector3(quarter, quarter, quarter));
|
|||
|
|
children[4] = new BoundsOctreeNode<T>(newLength, minSize, looseness, Center + new Vector3(-quarter, -quarter, -quarter));
|
|||
|
|
children[5] = new BoundsOctreeNode<T>(newLength, minSize, looseness, Center + new Vector3(quarter, -quarter, -quarter));
|
|||
|
|
children[6] = new BoundsOctreeNode<T>(newLength, minSize, looseness, Center + new Vector3(-quarter, -quarter, quarter));
|
|||
|
|
children[7] = new BoundsOctreeNode<T>(newLength, minSize, looseness, Center + new Vector3(quarter, -quarter, quarter));
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Merge all children into this node - the opposite of Split.
|
|||
|
|
/// Note: We only have to check one level down since a merge will never happen if the children already have children,
|
|||
|
|
/// since THAT won't happen unless there are already too many objects to merge.
|
|||
|
|
/// </summary>
|
|||
|
|
void Merge()
|
|||
|
|
{
|
|||
|
|
// Note: We know children != null or we wouldn't be merging
|
|||
|
|
for (int i = 0; i < 8; i++)
|
|||
|
|
{
|
|||
|
|
BoundsOctreeNode<T> curChild = children[i];
|
|||
|
|
int numObjects = curChild.objects.Count;
|
|||
|
|
for (int j = numObjects - 1; j >= 0; j--)
|
|||
|
|
{
|
|||
|
|
OctreeObject curObj = curChild.objects[j];
|
|||
|
|
objects.Add(curObj);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
// Remove the child nodes (and the objects in them - they've been added elsewhere now)
|
|||
|
|
children = null;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Checks if outerBounds encapsulates innerBounds.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="outerBounds">Outer bounds.</param>
|
|||
|
|
/// <param name="innerBounds">Inner bounds.</param>
|
|||
|
|
/// <returns>True if innerBounds is fully encapsulated by outerBounds.</returns>
|
|||
|
|
static bool Encapsulates(Bounds outerBounds, Bounds innerBounds)
|
|||
|
|
{
|
|||
|
|
return outerBounds.Contains(innerBounds.min) && outerBounds.Contains(innerBounds.max);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Checks if there are few enough objects in this node and its children that the children should all be merged into this.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <returns>True there are less or the same abount of objects in this and its children than numObjectsAllowed.</returns>
|
|||
|
|
bool ShouldMerge()
|
|||
|
|
{
|
|||
|
|
int totalObjects = objects.Count;
|
|||
|
|
if (children != null)
|
|||
|
|
{
|
|||
|
|
foreach (BoundsOctreeNode<T> child in children)
|
|||
|
|
{
|
|||
|
|
if (child.children != null)
|
|||
|
|
{
|
|||
|
|
// If any of the *children* have children, there are definitely too many to merge,
|
|||
|
|
// or the child woudl have been merged already
|
|||
|
|
return false;
|
|||
|
|
}
|
|||
|
|
totalObjects += child.objects.Count;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
return totalObjects <= NUM_OBJECTS_ALLOWED;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// A Dynamic, Loose Octree for storing any objects that can be described with AABB bounds
|
|||
|
|
// See also: PointOctree, where objects are stored as single points and some code can be simplified
|
|||
|
|
// Octree: An octree is a tree data structure which divides 3D space into smaller partitions (nodes)
|
|||
|
|
// and places objects into the appropriate nodes. This allows fast access to objects
|
|||
|
|
// in an area of interest without having to check every object.
|
|||
|
|
// Dynamic: The octree grows or shrinks as required when objects as added or removed
|
|||
|
|
// It also splits and merges nodes as appropriate. There is no maximum depth.
|
|||
|
|
// Nodes have a constant - numObjectsAllowed - which sets the amount of items allowed in a node before it splits.
|
|||
|
|
// Loose: The octree's nodes can be larger than 1/2 their parent's length and width, so they overlap to some extent.
|
|||
|
|
// This can alleviate the problem of even tiny objects ending up in large nodes if they're near boundaries.
|
|||
|
|
// A looseness value of 1.0 will make it a "normal" octree.
|
|||
|
|
// T: The content of the octree can be anything, since the bounds data is supplied separately.
|
|||
|
|
public class BoundsOctree<T>
|
|||
|
|
{
|
|||
|
|
// The total amount of objects currently in the tree
|
|||
|
|
public int Count { get; private set; }
|
|||
|
|
|
|||
|
|
// Root node of the octree
|
|||
|
|
BoundsOctreeNode<T> rootNode;
|
|||
|
|
|
|||
|
|
// Should be a value between 1 and 2. A multiplier for the base size of a node.
|
|||
|
|
// 1.0 is a "normal" octree, while values > 1 have overlap
|
|||
|
|
readonly float looseness;
|
|||
|
|
|
|||
|
|
// Size that the octree was on creation
|
|||
|
|
readonly float initialSize;
|
|||
|
|
|
|||
|
|
// Minimum side length that a node can be - essentially an alternative to having a max depth
|
|||
|
|
readonly float minSize;
|
|||
|
|
// For collision visualisation. Automatically removed in builds.
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Constructor for the bounds octree.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="initialWorldSize">Size of the sides of the initial node, in metres. The octree will never shrink smaller than this.</param>
|
|||
|
|
/// <param name="initialWorldPos">Position of the centre of the initial node.</param>
|
|||
|
|
/// <param name="minNodeSize">Nodes will stop splitting if the new nodes would be smaller than this (metres).</param>
|
|||
|
|
/// <param name="loosenessVal">Clamped between 1 and 2. Values > 1 let nodes overlap.</param>
|
|||
|
|
public BoundsOctree(float initialWorldSize, Vector3 initialWorldPos, float minNodeSize, float loosenessVal)
|
|||
|
|
{
|
|||
|
|
if (minNodeSize > initialWorldSize)
|
|||
|
|
{
|
|||
|
|
Debug.LogWarning("Minimum node size must be at least as big as the initial world size. Was: " + minNodeSize + " Adjusted to: " + initialWorldSize);
|
|||
|
|
minNodeSize = initialWorldSize;
|
|||
|
|
}
|
|||
|
|
Count = 0;
|
|||
|
|
initialSize = initialWorldSize;
|
|||
|
|
minSize = minNodeSize;
|
|||
|
|
looseness = Mathf.Clamp(loosenessVal, 1.0f, 2.0f);
|
|||
|
|
rootNode = new BoundsOctreeNode<T>(initialSize, minSize, looseness, initialWorldPos);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// #### PUBLIC METHODS ####
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Add an object.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="obj">Object to add.</param>
|
|||
|
|
/// <param name="objBounds">3D bounding box around the object.</param>
|
|||
|
|
public void Add(T obj, Bounds objBounds)
|
|||
|
|
{
|
|||
|
|
// Add object or expand the octree until it can be added
|
|||
|
|
int count = 0; // Safety check against infinite/excessive growth
|
|||
|
|
while (!rootNode.Add(obj, objBounds))
|
|||
|
|
{
|
|||
|
|
Grow(objBounds.center - rootNode.Center);
|
|||
|
|
if (++count > 20)
|
|||
|
|
{
|
|||
|
|
Debug.LogError("Aborted Add operation as it seemed to be going on forever (" + (count - 1) + ") attempts at growing the octree.");
|
|||
|
|
return;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
Count++;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Remove an object. Makes the assumption that the object only exists once in the tree.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="obj">Object to remove.</param>
|
|||
|
|
/// <returns>True if the object was removed successfully.</returns>
|
|||
|
|
public bool Remove(T obj)
|
|||
|
|
{
|
|||
|
|
bool removed = rootNode.Remove(obj);
|
|||
|
|
|
|||
|
|
// See if we can shrink the octree down now that we've removed the item
|
|||
|
|
if (removed)
|
|||
|
|
{
|
|||
|
|
Count--;
|
|||
|
|
Shrink();
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
return removed;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Removes the specified object at the given position. Makes the assumption that the object only exists once in the tree.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="obj">Object to remove.</param>
|
|||
|
|
/// <param name="objBounds">3D bounding box around the object.</param>
|
|||
|
|
/// <returns>True if the object was removed successfully.</returns>
|
|||
|
|
public bool Remove(T obj, Bounds objBounds)
|
|||
|
|
{
|
|||
|
|
bool removed = rootNode.Remove(obj, objBounds);
|
|||
|
|
|
|||
|
|
// See if we can shrink the octree down now that we've removed the item
|
|||
|
|
if (removed)
|
|||
|
|
{
|
|||
|
|
Count--;
|
|||
|
|
Shrink();
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
return removed;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Check if the specified bounds intersect with anything in the tree. See also: GetColliding.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="checkBounds">bounds to check.</param>
|
|||
|
|
/// <returns>True if there was a collision.</returns>
|
|||
|
|
public bool IsColliding(Bounds checkBounds)
|
|||
|
|
{
|
|||
|
|
return rootNode.IsColliding(ref checkBounds);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Check if the specified ray intersects with anything in the tree. See also: GetColliding.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="checkRay">ray to check.</param>
|
|||
|
|
/// <param name="maxDistance">distance to check.</param>
|
|||
|
|
/// <returns>True if there was a collision.</returns>
|
|||
|
|
public bool IsColliding(Ray checkRay, float maxDistance)
|
|||
|
|
{
|
|||
|
|
return rootNode.IsColliding(ref checkRay, maxDistance);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Returns an array of objects that intersect with the specified bounds, if any. Otherwise returns an empty array. See also: IsColliding.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="collidingWith">list to store intersections.</param>
|
|||
|
|
/// <param name="checkBounds">bounds to check.</param>
|
|||
|
|
/// <returns>Objects that intersect with the specified bounds.</returns>
|
|||
|
|
public void GetColliding(System.Collections.Generic.List<T> collidingWith, Bounds checkBounds)
|
|||
|
|
{
|
|||
|
|
rootNode.GetColliding(ref checkBounds, collidingWith);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Returns an array of objects that intersect with the specified ray, if any. Otherwise returns an empty array. See also: IsColliding.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="collidingWith">list to store intersections.</param>
|
|||
|
|
/// <param name="checkRay">ray to check.</param>
|
|||
|
|
/// <param name="maxDistance">distance to check.</param>
|
|||
|
|
/// <returns>Objects that intersect with the specified ray.</returns>
|
|||
|
|
public void GetColliding(System.Collections.Generic.List<T> collidingWith, Ray checkRay, float maxDistance = float.PositiveInfinity)
|
|||
|
|
{
|
|||
|
|
rootNode.GetColliding(ref checkRay, collidingWith, maxDistance);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
public System.Collections.Generic.List<T> GetWithinFrustum(Camera cam)
|
|||
|
|
{
|
|||
|
|
var planes = GeometryUtility.CalculateFrustumPlanes(cam);
|
|||
|
|
|
|||
|
|
var list = new System.Collections.Generic.List<T>();
|
|||
|
|
rootNode.GetWithinFrustum(planes, list);
|
|||
|
|
return list;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
public Bounds GetMaxBounds()
|
|||
|
|
{
|
|||
|
|
return rootNode.GetBounds();
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// #### PRIVATE METHODS ####
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Grow the octree to fit in all objects.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="direction">Direction to grow.</param>
|
|||
|
|
void Grow(Vector3 direction)
|
|||
|
|
{
|
|||
|
|
int xDirection = direction.x >= 0 ? 1 : -1;
|
|||
|
|
int yDirection = direction.y >= 0 ? 1 : -1;
|
|||
|
|
int zDirection = direction.z >= 0 ? 1 : -1;
|
|||
|
|
BoundsOctreeNode<T> oldRoot = rootNode;
|
|||
|
|
float half = rootNode.BaseLength / 2;
|
|||
|
|
float newLength = rootNode.BaseLength * 2;
|
|||
|
|
Vector3 newCenter = rootNode.Center + new Vector3(xDirection * half, yDirection * half, zDirection * half);
|
|||
|
|
|
|||
|
|
// Create a new, bigger octree root node
|
|||
|
|
rootNode = new BoundsOctreeNode<T>(newLength, minSize, looseness, newCenter);
|
|||
|
|
|
|||
|
|
if (oldRoot.HasAnyObjects())
|
|||
|
|
{
|
|||
|
|
// Create 7 new octree children to go with the old root as children of the new root
|
|||
|
|
int rootPos = rootNode.BestFitChild(oldRoot.Center);
|
|||
|
|
BoundsOctreeNode<T>[] children = new BoundsOctreeNode<T>[8];
|
|||
|
|
for (int i = 0; i < 8; i++)
|
|||
|
|
{
|
|||
|
|
if (i == rootPos)
|
|||
|
|
{
|
|||
|
|
children[i] = oldRoot;
|
|||
|
|
}
|
|||
|
|
else
|
|||
|
|
{
|
|||
|
|
xDirection = i % 2 == 0 ? -1 : 1;
|
|||
|
|
yDirection = i > 3 ? -1 : 1;
|
|||
|
|
zDirection = (i < 2 || (i > 3 && i < 6)) ? -1 : 1;
|
|||
|
|
children[i] = new BoundsOctreeNode<T>(oldRoot.BaseLength, minSize, looseness, newCenter + new Vector3(xDirection * half, yDirection * half, zDirection * half));
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// Attach the new children to the new root node
|
|||
|
|
rootNode.SetChildren(children);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Shrink the octree if possible, else leave it the same.
|
|||
|
|
/// </summary>
|
|||
|
|
void Shrink()
|
|||
|
|
{
|
|||
|
|
rootNode = rootNode.ShrinkIfPossible(initialSize);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|