Fill polygon in unity 3d - unity3d

Question

I've some problem when draw manual in unity 2d.
I used list vector to draw polygon, but I can't fill it.
I also read this tutorial: http://forum.unity3d.com/threads/draw-polygon.54092/
But it's seem I need to convert polygon to triangles.(because my polygon is complex so convert to triangles is hard. I need to use some algorithm like Ear clipping...).
Please help me an easy way to fill it. (I think unity is top of game engine, then have some way to do it easiest).
Thanks so so much.

Answer 1

You are stuck with converting to mesh to get fill to work... GPUs(shaders) can only fill the interior spaces of triangles... This is fairly easy if you are working with closed convex polygons. Polygons with concave sections will take a bit more complicated algorithm to convert to mesh, but it seems you've already done some research on the subject (you mentioned ear clipping).
Good luck implementing your polygon list to triangle algo :)

Answer 2

I can offer Poisson-Disc algorithm remodel UniformPoissonDiskSampler.cs like :
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);
}
}
figures_Included:
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;
}
and 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; }
}