我在统一 2d 中绘制手册时遇到了一些问题。 我使用列表向量来绘制多边形，但我无法填充它。 我还阅读了本教程：http://forum.unity3d.com/threads/draw-polygon.54092/ 但似乎我需要将多边形转换为三角形。（因为我的多边形很复杂，所以转换为三角形很难。我需要使用一些算法，比如剪耳......）。
请帮我一个简单的方法来填充它。 （我认为统一是游戏引擎的顶级，然后有一些方法可以做到最简单）。
非常感谢。
【问题讨论】：
标签： unity3d unityscript
您被困在转换为网格以使填充工作... GPU（着色器）只能填充三角形的内部空间...如果您使用封闭的凸多边形，这相当容易。具有凹面部分的多边形将需要更复杂的算法才能转换为网格，但您似乎已经对该主题进行了一些研究（您提到了剪耳）。
祝你好运将你的多边形列表实现为三角形算法:)
【讨论】：
我可以提供Poisson-Disc algorithm remodel UniformPoissonDiskSampler.cs 之类的：
using System;
using System.Collections.Generic;
using UnityEngine;
namespace AwesomeNamespace
{
public static class UniformPoissonDiskSampler
{
public const int DefaultPointsPerIteration = 30;
static readonly float SquareRootTwo = (float)Math.Sqrt(2);
struct Settings
{
public UnityEngine.Vector2 TopLeft, LowerRight, Center;
public UnityEngine.Vector2 Dimensions;
public float? RejectionSqDistance;
public float MinimumDistance;
public float CellSize;
public int GridWidth, GridHeight;
}
struct State
{
public UnityEngine.Vector2?[,] Grid;
public List<UnityEngine.Vector2> ActivePoints, Points;
}
public static List<UnityEngine.Vector2> SampleCircle(UnityEngine.Vector2 center, float radius, float minimumDistance)
{
return SampleCircle(center, radius, minimumDistance, DefaultPointsPerIteration);
}
public static List<UnityEngine.Vector2> SampleCircle(UnityEngine.Vector2 center, float radius, float minimumDistance, int pointsPerIteration)
{
return Sample(center - new UnityEngine.Vector2(radius, radius), center + new UnityEngine.Vector2(radius, radius), radius, minimumDistance, pointsPerIteration, null);
}
public static List<UnityEngine.Vector2> SampleRectangle(UnityEngine.Vector2 topLeft, UnityEngine.Vector2 lowerRight, float minimumDistance)
{
return SampleRectangle(topLeft, lowerRight, minimumDistance, DefaultPointsPerIteration);
}
public static List<UnityEngine.Vector2> SampleRectangle(UnityEngine.Vector2 topLeft, UnityEngine.Vector2 lowerRight, float minimumDistance, int pointsPerIteration)
{
return Sample(topLeft, lowerRight, null, minimumDistance, pointsPerIteration, null);
}
public static List<UnityEngine.Vector2> SamplePolygon(UnityEditor.Experimental.TerrainAPI.Processing.InMetric metric, float minimumDistance)
{
return Sample(null, null, null, minimumDistance, DefaultPointsPerIteration, metric);
}
static List<UnityEngine.Vector2> Sample(UnityEngine.Vector2? topLeft, UnityEngine.Vector2? lowerRight, float? rejectionDistance, float minimumDistance, int pointsPerIteration, UnityEditor.Experimental.TerrainAPI.Processing.InMetric metric = null)
{
if (!topLeft.HasValue && !lowerRight.HasValue && metric != null)
{
topLeft = new Vector2(metric.minpointx, metric.minpointz);
lowerRight = new Vector2(metric.maxpointx, metric.maxpointz);
}
var settings = new Settings
{
TopLeft = (Vector2)topLeft,
LowerRight = (Vector2)lowerRight,
Dimensions = (Vector2)lowerRight - (Vector2)topLeft,
Center = ((Vector2)topLeft + (Vector2)lowerRight) / 2,
CellSize = minimumDistance / SquareRootTwo,
MinimumDistance = minimumDistance,
RejectionSqDistance = rejectionDistance == null ? null : rejectionDistance * rejectionDistance
};
settings.GridWidth = (int)(settings.Dimensions.x / settings.CellSize) + 1;
settings.GridHeight = (int)(settings.Dimensions.y / settings.CellSize) + 1;
// Debug.Log("settings.GridWidth"+settings.GridWidth+"settings.GridHeight"+settings.GridHeight);
var state = new State
{
Grid = new UnityEngine.Vector2?[settings.GridWidth, settings.GridHeight],
ActivePoints = new List<UnityEngine.Vector2>(),
Points = new List<UnityEngine.Vector2>()
};
AddFirstPoint(ref settings, ref state, (metric == null) ? null : metric);
while (state.ActivePoints.Count != 0)
{
var listIndex = RandomHelper.Random.Next(state.ActivePoints.Count);
var point = state.ActivePoints[listIndex];
var found = false;
for (var k = 0; k < pointsPerIteration; k++)
found |= AddNextPoint(point, ref settings, ref state, (metric == null) ? null : metric);
if (!found)
state.ActivePoints.RemoveAt(listIndex);
}
return state.Points;
}
static void AddFirstPoint(ref Settings settings,
ref State state,
UnityEditor.Experimental.TerrainAPI.Processing.InMetric metric = null)
{
var added = false;
while (!added)
{
var d = RandomHelper.Random.NextDouble();
var xr = settings.TopLeft.x + settings.Dimensions.x * d;
d = RandomHelper.Random.NextDouble();
var yr = settings.TopLeft.y + settings.Dimensions.y * d;
var p = new UnityEngine.Vector2((float)xr, (float)yr);
if (settings.RejectionSqDistance != null && DistanceSquared(settings.Center, p) > settings.RejectionSqDistance)
continue;
added = true;
if (UnityEditor.Experimental.TerrainAPI.Processing.figures_Included(p.x, p.y, metric.metricIn, metric.count) == true)
{
var index = Denormalize(p, settings.TopLeft, settings.CellSize);
state.Grid[(int)index.x, (int)index.y] = p;
state.ActivePoints.Add(p);
state.Points.Add(p);
}
else
{
AddFirstPoint(ref settings, ref state, metric);
}
}
}
static float DistanceSquared(Vector2 A, Vector2 B)
{
return (float)Math.Pow(Math.Sqrt(Math.Pow((A.x - B.x), 2) + Math.Pow((A.y - B.y), 2)), 2);
}
static bool AddNextPoint(UnityEngine.Vector2 point,
ref Settings settings,
ref State state,
UnityEditor.Experimental.TerrainAPI.Processing.InMetric metric = null)
{
var found = false;
var q = GenerateRandomAround(point, settings.MinimumDistance);
if (metric != null)
{
if (UnityEditor.Experimental.TerrainAPI.Processing.figures_Included(q.x, q.y, metric.metricIn, metric.count) == true &&
q.x >= settings.TopLeft.x && q.x < settings.LowerRight.x &&
q.y > settings.TopLeft.y && q.y < settings.LowerRight.y &&
(settings.RejectionSqDistance == null || DistanceSquared(settings.Center, q) <= settings.RejectionSqDistance))
{
var qIndex = Denormalize(q, settings.TopLeft, settings.CellSize);
var tooClose = false;
for (var i = (int)Math.Max(0, qIndex.x - 2); i < Math.Min(settings.GridWidth, qIndex.x + 3) && !tooClose; i++)
for (var j = (int)Math.Max(0, qIndex.y - 2); j < Math.Min(settings.GridHeight, qIndex.y + 3) && !tooClose; j++)
if (state.Grid[i, j].HasValue && Vector2.Distance(state.Grid[i, j].Value, q) < settings.MinimumDistance)
tooClose = true;
if (!tooClose)
{
found = true;
state.ActivePoints.Add(q);
state.Points.Add(q);
state.Grid[(int)qIndex.x, (int)qIndex.y] = q;
}
}
}
else
{
if (q.x >= settings.TopLeft.x && q.x < settings.LowerRight.x &&
q.y > settings.TopLeft.y && q.y < settings.LowerRight.y &&
(settings.RejectionSqDistance == null || DistanceSquared(settings.Center, q) <= settings.RejectionSqDistance))
{
var qIndex = Denormalize(q, settings.TopLeft, settings.CellSize);
var tooClose = false;
for (var i = (int)Math.Max(0, qIndex.x - 2); i < Math.Min(settings.GridWidth, qIndex.x + 3) && !tooClose; i++)
for (var j = (int)Math.Max(0, qIndex.y - 2); j < Math.Min(settings.GridHeight, qIndex.y + 3) && !tooClose; j++)
if (state.Grid[i, j].HasValue && Vector2.Distance(state.Grid[i, j].Value, q) < settings.MinimumDistance)
tooClose = true;
if (!tooClose)
{
found = true;
state.ActivePoints.Add(q);
state.Points.Add(q);
state.Grid[(int)qIndex.x, (int)qIndex.y] = q;
}
}
}
return found;
}
static Vector2 GenerateRandomAround(Vector2 center, float minimumDistance)
{
var d = RandomHelper.Random.NextDouble();
var radius = minimumDistance + minimumDistance * d;
d = RandomHelper.Random.NextDouble();
var angle = MathHelper.TwoPi * d;
var newX = radius * Math.Sin(angle);
var newY = radius * Math.Cos(angle);
return new Vector2((float)(center.x + newX), (float)(center.y + newY));
}
static Vector2 Denormalize(Vector2 point, Vector2 origin, double cellSize)
{
return new Vector2((int)((point.x - origin.x) / cellSize), (int)((point.y - origin.y) / cellSize));
}
}
public static class RandomHelper
{
public static readonly System.Random Random = new System.Random();
}
public static class MathHelper
{
public const float Pi = (float)Math.PI;
public const float HalfPi = (float)(Math.PI / 2);
public const float TwoPi = (float)(Math.PI * 2);
}
}
数字_包括：
public static bool figures_Included(float xPoint, float yPoint, float[] metricIn, int n)
{
float X = xPoint;
float Y = yPoint;
int npol = n;
int i, j;
bool res = false;
float[] XYpol = metricIn;
for (i = 0, j = npol - 1; i < npol; j = i++)
{
if ((((XYpol[i * 2 + 1] <= Y) && (Y < XYpol[j * 2 + 1])) ||
((XYpol[j * 2 + 1] <= Y) && (Y < XYpol[i * 2 + 1]))) &&
(X < (XYpol[j * 2] - XYpol[i * 2]) * (Y - XYpol[i * 2 + 1]) /
(XYpol[j * 2 + 1] - XYpol[i * 2 + 1]) + XYpol[i * 2]))
{
res = !res;
}
}
return res;
}
和 InMetric ：
static public InMetric getmetricIn(List<Vector3> drawcoord, bool editingmode = true)
{
float mapoffsetx = 0;
float mapoffsety = 0;
if (editingmode == true)
{
mapoffsetx = Main.mainSatting.mapoffsetx;
mapoffsety = Main.mainSatting.mapoffsetz;
}
else
{
mapoffsetx = 0;
mapoffsety = 0;
}
if (drawcoord[0].x != drawcoord[drawcoord.Count - 1].x && drawcoord[0].z != drawcoord[drawcoord.Count - 1].z) //если линия, ограничивающая полигон не замкнута
drawcoord.Add(drawcoord[0]); //добавляем замыкающую вершину
float[] metricIn = new float[drawcoord.Count * 2]; //дополнительный массив вершин, пересчитанный для проверки нахождения точки внутри полигона
drawcoord[0] = new Vector3(drawcoord[0].x - mapoffsetx, 0, drawcoord[0].z - mapoffsety); //расчет 0-ой вершины в единицах Unity (метры)
metricIn[0] = drawcoord[0].x;
metricIn[1] = drawcoord[0].z; //запись 0-ой вершины в дополнительный массив. x-координаты под четными индексами, Z-координаты под нечетными индексами
float minpointx = drawcoord[0].x; //минимальная x-координата
float maxpointx = drawcoord[0].x; //максимальная х-координата
float minpointz = drawcoord[0].z; //минимальная y-координата
float maxpointz = drawcoord[0].z; //максимальная у-координата
/*Цикл обработки вершин. начинается 1-ой вершины*/
for (int i = 1; i < drawcoord.Count; i++)
{
drawcoord[i] = new Vector3(drawcoord[i].x - mapoffsetx, 0, drawcoord[i].z - mapoffsety); //расчет i-ой вершины в единицах Unity (метры)
metricIn[i * 2] = drawcoord[i].x; //запись i-ой вершины в дополнительный массив. x-координаты под четными индексами
metricIn[i * 2 + 1] = drawcoord[i].z; //запись i-ой вершины в дополнительный массив. z-координаты под нечетными индексами
/*поиск максимальных и минимальных координат по x и максимальных и минимальных координат по z*/
if (drawcoord[i].x < minpointx)
minpointx = drawcoord[i].x;
if (drawcoord[i].x > maxpointx)
maxpointx = drawcoord[i].x;
if (drawcoord[i].z < minpointz)
minpointz = drawcoord[i].z;
if (drawcoord[i].z > maxpointz)
maxpointz = drawcoord[i].z;
}
InMetric metric = new InMetric();
metric.metricIn = metricIn;
metric.minpointx = minpointx;
metric.maxpointx = maxpointx;
metric.minpointz = minpointz;
metric.maxpointz = maxpointz;
metric.drawcoord = drawcoord;
metric.count = drawcoord.Count;
return metric;
}
public class InMetric
{
public float minpointx { get; set; }
public float maxpointx { get; set; }
public float minpointz { get; set; }
public float maxpointz { get; set; }
public float[] metricIn { get; set; }
public List<Vector3> drawcoord { get; set; }
public int count { get; set; }
}
【讨论】：