VolumetricFog 2.0

Assets/Editor/CreatePerlinFogRuntime.cs

@@ -0,0 +1,93 @@
+#if UNITY_EDITOR
+using UnityEngine;
+using UnityEditor;
+using System.IO;
+
+public class CreatePerlinFogAsset : EditorWindow
+{
+    public int size = 64;
+    public float scale = 0.05f;
+    public int seed = 1337;
+    public string assetPath = "Assets/FogNoise.asset";
+
+    [MenuItem("Tools/Generate Fog Texture3D")]
+    static void OpenWindow() => GetWindow<CreatePerlinFogAsset>("Generate Fog 3D");
+
+    void OnGUI()
+    {
+        GUILayout.Label("Generate 3D Perlin Fog Texture", EditorStyles.boldLabel);
+        size = EditorGUILayout.IntField("Size", size);
+        scale = EditorGUILayout.FloatField("Scale", scale);
+        seed = EditorGUILayout.IntField("Seed", seed);
+        assetPath = EditorGUILayout.TextField("Asset Path", assetPath);
+
+        if (GUILayout.Button("Generate and Save"))
+        {
+            var tex = CreatePerlin3D(size, scale, seed);
+            tex.wrapMode = TextureWrapMode.Repeat;
+            tex.filterMode = FilterMode.Trilinear;
+            tex.Apply();
+
+            // ensure directory exists
+            var dir = Path.GetDirectoryName(assetPath);
+            if (!string.IsNullOrEmpty(dir) && !Directory.Exists(dir))
+                Directory.CreateDirectory(dir);
+
+            AssetDatabase.CreateAsset(tex, assetPath);
+            AssetDatabase.SaveAssets();
+            AssetDatabase.Refresh();
+            EditorUtility.FocusProjectWindow();
+            Selection.activeObject = AssetDatabase.LoadAssetAtPath<Texture3D>(assetPath);
+            Debug.Log($"Texture3D saved to {assetPath}");
+        }
+    }
+
+    static Texture3D CreatePerlin3D(int size, float scale, int seed)
+    {
+        var tex = new Texture3D(size, size, size, TextureFormat.RGBA32, false);
+        var colors = new Color[size * size * size];
+        System.Random rng = new System.Random(seed);
+        float offsetX = (float)rng.NextDouble() * 10000f;
+        float offsetY = (float)rng.NextDouble() * 10000f;
+        float offsetZ = (float)rng.NextDouble() * 10000f;
+
+        int idx = 0;
+        for (int z = 0; z < size; z++)
+        {
+            float wz = (z + offsetZ) * scale;
+            for (int y = 0; y < size; y++)
+            {
+                float wy = (y + offsetY) * scale;
+                for (int x = 0; x < size; x++)
+                {
+                    float wx = (x + offsetX) * scale;
+                    float n = FractalPerlin(wx, wy, wz, 3);
+                    colors[idx++] = new Color(n, n, n, n);
+                }
+            }
+        }
+
+        tex.SetPixels(colors);
+        tex.Apply();
+        return tex;
+    }
+
+    static float FractalPerlin(float x, float y, float z, int octaves)
+    {
+        float amp = 1f;
+        float freq = 1f;
+        float sum = 0f;
+        float max = 0f;
+        for (int i = 0; i < octaves; i++)
+        {
+            sum += amp * Mathf.PerlinNoise(x * freq, y * freq);
+            sum += amp * Mathf.PerlinNoise(y * freq, z * freq);
+            sum += amp * Mathf.PerlinNoise(z * freq, x * freq);
+            max += 3f * amp;
+            amp *= 0.5f;
+            freq *= 2f;
+        }
+        return Mathf.Clamp01(sum / max);
+    }
+}
+#endif