20240422

Unity/MeshGeneration/Factories/TerrainStrategies/FlatSphereTerrainStrategy.cs

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+using System.Collections.Generic;
+using UnityEngine;
+using Mapbox.Unity.MeshGeneration.Data;
+using Mapbox.Unity.Map;
+using Mapbox.Utils;
+using Mapbox.Unity.Utilities;
+
+namespace Mapbox.Unity.MeshGeneration.Factories.TerrainStrategies
+{
+
+	public class FlatSphereTerrainStrategy : TerrainStrategy
+	{
+		public float Radius { get { return _elevationOptions.modificationOptions.earthRadius; } }
+		public override int RequiredVertexCount
+		{
+			get { return _elevationOptions.modificationOptions.sampleCount * _elevationOptions.modificationOptions.sampleCount; }
+		}
+
+		public override void Initialize(ElevationLayerProperties elOptions)
+		{
+			_elevationOptions = elOptions;
+		}
+
+		public override void RegisterTile(UnityTile tile)
+		{
+			if (_elevationOptions.unityLayerOptions.addToLayer && tile.gameObject.layer != _elevationOptions.unityLayerOptions.layerId)
+			{
+				tile.gameObject.layer = _elevationOptions.unityLayerOptions.layerId;
+			}
+
+			if ((int)tile.ElevationType != (int)ElevationLayerType.GlobeTerrain ||
+				tile.MeshFilter.sharedMesh.vertexCount != RequiredVertexCount)
+			{
+				tile.MeshFilter.sharedMesh.Clear();
+				tile.ElevationType = TileTerrainType.Globe;
+			}
+
+			GenerateTerrainMesh(tile);
+		}
+
+		void GenerateTerrainMesh(UnityTile tile)
+		{
+			var verts = new List<Vector3>();
+			var _sampleCount = _elevationOptions.modificationOptions.sampleCount;
+			var _radius = _elevationOptions.modificationOptions.earthRadius;
+			for (float x = 0; x < _sampleCount; x++)
+			{
+				for (float y = 0; y < _sampleCount; y++)
+				{
+					var xx = Mathf.Lerp((float)tile.Rect.Min.x, ((float)tile.Rect.Min.x + (float)tile.Rect.Size.x),
+						x / (_sampleCount - 1));
+					var yy = Mathf.Lerp((float)tile.Rect.Max.y, ((float)tile.Rect.Max.y + (float)tile.Rect.Size.y),
+						y / (_sampleCount - 1));
+
+					var ll = Conversions.MetersToLatLon(new Vector2d(xx, yy));
+
+					var latitude = (float)(Mathf.Deg2Rad * ll.x);
+					var longitude = (float)(Mathf.Deg2Rad * ll.y);
+
+					float xPos = (_radius) * Mathf.Cos(latitude) * Mathf.Cos(longitude);
+					float zPos = (_radius) * Mathf.Cos(latitude) * Mathf.Sin(longitude);
+					float yPos = (_radius) * Mathf.Sin(latitude);
+
+					var pp = new Vector3(xPos, yPos, zPos);
+					verts.Add(pp);
+				}
+			}
+
+			var trilist = new List<int>();
+			for (int y = 0; y < _sampleCount - 1; y++)
+			{
+				for (int x = 0; x < _sampleCount - 1; x++)
+				{
+					trilist.Add((y * _sampleCount) + x);
+					trilist.Add((y * _sampleCount) + x + _sampleCount + 1);
+					trilist.Add((y * _sampleCount) + x + _sampleCount);
+
+					trilist.Add((y * _sampleCount) + x);
+					trilist.Add((y * _sampleCount) + x + 1);
+					trilist.Add((y * _sampleCount) + x + _sampleCount + 1);
+				}
+			}
+
+			var uvlist = new List<Vector2>();
+			var step = 1f / (_sampleCount - 1);
+			for (int i = 0; i < _sampleCount; i++)
+			{
+				for (int j = 0; j < _sampleCount; j++)
+				{
+					uvlist.Add(new Vector2(i * step, (j * step)));
+				}
+			}
+
+			tile.MeshFilter.sharedMesh.SetVertices(verts);
+			tile.MeshFilter.sharedMesh.SetTriangles(trilist, 0);
+			tile.MeshFilter.sharedMesh.SetUVs(0, uvlist);
+			tile.MeshFilter.sharedMesh.RecalculateBounds();
+			tile.MeshFilter.sharedMesh.RecalculateNormals();
+
+			tile.transform.localPosition = Mapbox.Unity.Constants.Math.Vector3Zero;
+		}
+
+		public override void UnregisterTile(UnityTile tile)
+		{
+
+		}
+	}
+
+}