unitycoder · October 22, 2025 13:32 · Oct 22, 2025
diff --git a/StarfieldMeshBuilder.cs b/StarfieldMeshBuilder.cs
@@ -0,0 +1,121 @@
+using System;
+using UnityEngine;
+using UnityEngine.Rendering;
+using Random = System.Random;
+
+namespace StellarConquest.Presentation.Unity
+{
+    public class StarfieldMeshBuilder : MonoBehaviour
+    {
+        public float SphereRadius = 4000;
+        public int StarsCount = 0;
+        public int Seed = 0;
+        [Range(1, 15)]
+        public float StarSizeScale = 4.5f;
+        [SerializeField] AnimationCurve StarSize = new AnimationCurve(new Keyframe(0, 1), new Keyframe(1, 10));
+        [SerializeField] AnimationCurve Brightness = new AnimationCurve(new Keyframe(0, 0.8f), new Keyframe(1, 2f));
+        [SerializeField] Gradient StarColor = new Gradient();
+
+        private MeshFilter _MeshFilter;
+        private Mesh _Mesh;
+        private bool _IsDirty = false;
+
+#if UNITY_EDITOR
+        private void OnValidate()
+        {
+            _IsDirty = true;
+        }
+#endif
+
+        private void Update()
+        {
+            if (_IsDirty)
+                Build();
+        }
+
+        [ContextMenu("Build")]
+        public void Build()
+        {
+            _IsDirty = false;
+
+            if (!_MeshFilter)
+                _MeshFilter = GetComponent<MeshFilter>();
+
+            if (_Mesh == null)
+            {
+                _Mesh = new Mesh() { indexFormat = IndexFormat.UInt32 };
+                _Mesh.name = name;
+                _MeshFilter.mesh = _Mesh;
+            }
+            _Mesh.Clear();
+
+            Vector3[] vertices = new Vector3[4 * StarsCount];
+            int[] triangles = new int[3 * 2 * StarsCount];
+            Vector2[] uvs = new Vector2[vertices.Length];
+            Color[] colors = new Color[vertices.Length];
+            Random rnd = new Random(Seed);
+
+            for (int i = 0; i < StarsCount; i++)
+            {
+                //calc position
+                int index = i * 4;
+                float distance = SphereRadius + SphereRadius * NextFloat() / 2f;
+                float size = StarSize.Evaluate(NextFloat()) * StarSizeScale;
+
+                Vector3 pos = NextOnSphere() * distance;
+                Vector3 up = Vector3.Cross(pos, Math.Abs(pos.z) > distance / 2 ? Vector3.up : Vector3.right).normalized;
+                Vector3 left = Vector3.Cross(-up, pos).normalized;
+
+                //vertices
+                vertices[index + 0] = pos + (left + up) * size;
+                vertices[index + 1] = pos + (-left + up) * size;
+                vertices[index + 2] = pos + (-left - up) * size;
+                vertices[index + 3] = pos + (left - up) * size;
+
+                //uv
+                uvs[index + 0] = new Vector2(0, 0);
+                uvs[index + 1] = new Vector2(1, 0);
+                uvs[index + 2] = new Vector2(1, 1);
+                uvs[index + 3] = new Vector2(0, 1);
+
+                //triangles
+                var iTr = i * 2 * 3;
+                triangles[iTr++] = index + 0;
+                triangles[iTr++] = index + 1;
+                triangles[iTr++] = index + 2;
+
+                triangles[iTr++] = index + 0;
+                triangles[iTr++] = index + 2;
+                triangles[iTr++] = index + 3;
+
+                //color
+                Color color = Brightness.Evaluate(NextFloat()) * StarColor.Evaluate(NextFloat());
+                colors[index + 0] = colors[index + 1] = colors[index + 2] = colors[index + 3] = color;
+            }
+
+            _Mesh.SetVertices(vertices);
+            _Mesh.SetUVs(0, uvs);
+            _Mesh.SetTriangles(triangles, 0);
+            _Mesh.SetColors(colors);
+
+            _Mesh.RecalculateNormals();
+            _Mesh.RecalculateBounds();
+
+            float NextFloat()
+            {
+                return (float)rnd.NextDouble();
+            }
+
+            Vector3 NextOnSphere()
+            {
+                var theta = 2 * Math.PI * rnd.NextDouble();
+                var phi = Math.Acos(2 * rnd.NextDouble() - 1.0);
+                var sinPhi = Math.Sin(phi);
+                var x = Math.Cos(theta) * sinPhi;
+                var y = Math.Sin(theta) * sinPhi;
+                var z = Math.Cos(phi);
+                return new Vector3((float)x, (float)y, (float)z);
+            }
+        }
+    }
+}