Симуляция работает

src/client/java/su/divan2000/veila/client/render/PostProcessingManager.java

@@ -13,6 +13,7 @@ import su.divan2000.veila.client.gl.FullscreenQuad;
 import su.divan2000.veila.client.gl.GLProgram;
 import su.divan2000.veila.client.gl.GLShader;
 import su.divan2000.veila.client.gl.ResourceUtil;
+import su.divan2000.veila.client.render.fog.FogSimulationManager;
 import su.divan2000.veila.client.render.fog.FogSystem;
 import su.divan2000.veila.client.render.fog.FogWorldVolume;
 
@@ -154,7 +155,7 @@ public class PostProcessingManager {
 
         GL11.glBindTexture(
                 GL12.GL_TEXTURE_3D,
-                FogWorldVolume.getTexture()
+                FogSimulationManager.getCurrentDensityTexture()
         );
 
         GL20.glUniform1i(

src/client/java/su/divan2000/veila/client/render/fog/FogChunkStreamer.java

@@ -242,6 +242,8 @@ public final class FogChunkStreamer {
         int physicalIndex = physicalZ * FogWorldVolume.CHUNKS_X + physicalX;
 
         FogWorldVolume.uploadZeros(physicalX, physicalZ);
+        FogDensityTextures.clearColumn(physicalX, physicalZ);
+
         statuses[physicalIndex] = ChunkStatus.PENDING;
         readyToUpload[physicalIndex] = false;
     }

src/client/java/su/divan2000/veila/client/render/fog/FogDensityTextures.java

@@ -0,0 +1,121 @@
+package su.divan2000.veila.client.render.fog;
+
+import org.lwjgl.BufferUtils;
+import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL12;
+import org.lwjgl.opengl.GL30;
+
+import java.nio.ByteBuffer;
+import java.nio.FloatBuffer;
+
+public final class FogDensityTextures {
+
+    private static int textureA = -1;
+    private static int textureB = -1;
+    private static int readIndex = 0;
+
+    // Float буфер с нулями для одного столбца 16×384×16
+    private static final FloatBuffer ZEROS_BUFFER =
+            BufferUtils.createFloatBuffer(
+                    FogWorldVolume.CHUNK_SIZE *
+                            FogWorldVolume.SIZE_Y *
+                            FogWorldVolume.CHUNK_SIZE
+            );
+
+    static {
+        int size = FogWorldVolume.CHUNK_SIZE * FogWorldVolume.SIZE_Y * FogWorldVolume.CHUNK_SIZE;
+        for (int i = 0; i < size; i++) {
+            ZEROS_BUFFER.put(0.0f);
+        }
+        ZEROS_BUFFER.flip();
+    }
+
+    private FogDensityTextures() {
+    }
+
+    public static void init() {
+        if (textureA != -1) return;
+
+        textureA = createDensityTexture();
+        textureB = createDensityTexture();
+    }
+
+    private static int createDensityTexture() {
+        int texture = GL11.glGenTextures();
+
+        GL11.glBindTexture(GL12.GL_TEXTURE_3D, texture);
+
+        GL30.glTexImage3D(
+                GL12.GL_TEXTURE_3D,
+                0,
+                GL30.GL_R16F,
+                FogWorldVolume.SIZE_X,
+                FogWorldVolume.SIZE_Y,
+                FogWorldVolume.SIZE_Z,
+                0,
+                GL11.GL_RED,
+                GL11.GL_FLOAT,
+                (ByteBuffer) null
+        );
+
+        GL11.glTexParameteri(GL12.GL_TEXTURE_3D, GL11.GL_TEXTURE_MIN_FILTER, GL11.GL_LINEAR);
+        GL11.glTexParameteri(GL12.GL_TEXTURE_3D, GL11.GL_TEXTURE_MAG_FILTER, GL11.GL_LINEAR);
+
+        GL11.glTexParameteri(GL12.GL_TEXTURE_3D, GL12.GL_TEXTURE_WRAP_S, GL12.GL_REPEAT);
+        GL11.glTexParameteri(GL12.GL_TEXTURE_3D, GL12.GL_TEXTURE_WRAP_T, GL12.GL_CLAMP_TO_EDGE);
+        GL11.glTexParameteri(GL12.GL_TEXTURE_3D, GL12.GL_TEXTURE_WRAP_R, GL12.GL_REPEAT);
+
+        GL11.glBindTexture(GL12.GL_TEXTURE_3D, 0);
+
+        return texture;
+    }
+
+    public static void swap() {
+        readIndex = 1 - readIndex;
+    }
+
+    public static int getReadTexture() {
+        return readIndex == 0 ? textureA : textureB;
+    }
+
+    public static int getWriteTexture() {
+        return readIndex == 0 ? textureB : textureA;
+    }
+
+    /**
+     * Обнуляет столбец (один чанк) в ОБОИХ density текстурах.
+     * Вызывается при смене окна, чтобы не было фантомного тумана.
+     */
+    public static void clearColumn(int textureChunkX, int textureChunkZ) {
+        clearColumnInTexture(textureA, textureChunkX, textureChunkZ);
+        clearColumnInTexture(textureB, textureChunkX, textureChunkZ);
+    }
+
+    private static void clearColumnInTexture(int texture, int textureChunkX, int textureChunkZ) {
+        GL11.glBindTexture(GL12.GL_TEXTURE_3D, texture);
+
+        GL11.glPixelStorei(GL11.GL_UNPACK_ALIGNMENT, 1);
+        GL11.glPixelStorei(GL11.GL_UNPACK_ROW_LENGTH, 0);
+        GL11.glPixelStorei(GL11.GL_UNPACK_SKIP_PIXELS, 0);
+        GL11.glPixelStorei(GL11.GL_UNPACK_SKIP_ROWS, 0);
+
+        // Сбрасываем position буфера
+        ZEROS_BUFFER.rewind();
+
+        GL30.glTexSubImage3D(
+                GL12.GL_TEXTURE_3D,
+                0,
+                textureChunkX * FogWorldVolume.CHUNK_SIZE,
+                0,
+                textureChunkZ * FogWorldVolume.CHUNK_SIZE,
+                FogWorldVolume.CHUNK_SIZE,
+                FogWorldVolume.SIZE_Y,
+                FogWorldVolume.CHUNK_SIZE,
+                GL11.GL_RED,
+                GL11.GL_FLOAT,
+                ZEROS_BUFFER
+        );
+
+        GL11.glBindTexture(GL12.GL_TEXTURE_3D, 0);
+    }
+}

src/client/java/su/divan2000/veila/client/render/fog/FogSimulationManager.java

@@ -0,0 +1,73 @@
+package su.divan2000.veila.client.render.fog;
+
+public final class FogSimulationManager {
+
+    private static boolean initialized = false;
+    private static long lastSimulationTime = 0;
+
+    // Симулируем каждые 100 мс (10 раз в секунду)
+    private static final long SIMULATION_INTERVAL_NS = 100_000_000L;
+
+    private static float globalEmissionMultiplier = 1.0f;
+    private static float globalAbsorptionMultiplier = 1.0f;
+    private static float globalDecay = 0.01f;
+    private static float diffusionRate = 0.1f;
+    private static float upDiffusion = 0.9f;
+    private static float downDiffusion = 1.1f;
+    private static float horizontalDiffusion = 1.0f;
+
+    private FogSimulationManager() {
+    }
+
+    public static void init() {
+        if (initialized) return;
+
+        FogDensityTextures.init();
+        FogSimulationShader.init();
+
+        initialized = true;
+        lastSimulationTime = System.nanoTime();
+    }
+
+    /**
+     * Вызывается из RENDER THREAD в beginRender()
+     */
+    public static void update() {
+        if (!initialized) return;
+
+        long currentTime = System.nanoTime();
+
+        if (currentTime - lastSimulationTime >= SIMULATION_INTERVAL_NS) {
+            lastSimulationTime = currentTime;
+            simulate();
+        }
+    }
+
+    private static void simulate() {
+        FogSimulationShader.simulate(
+                globalEmissionMultiplier,
+                globalAbsorptionMultiplier,
+                globalDecay,
+                diffusionRate,
+                upDiffusion,
+                downDiffusion,
+                horizontalDiffusion
+        );
+    }
+
+    public static int getCurrentDensityTexture() {
+        return FogDensityTextures.getReadTexture();
+    }
+
+    public static void setGlobalEmissionMultiplier(float value) {
+        globalEmissionMultiplier = value;
+    }
+
+    public static void setGlobalAbsorptionMultiplier(float value) {
+        globalAbsorptionMultiplier = value;
+    }
+
+    public static void setGlobalDecay(float value) {
+        globalDecay = value;
+    }
+}

src/client/java/su/divan2000/veila/client/render/fog/FogSimulationShader.java

@@ -0,0 +1,243 @@
+package su.divan2000.veila.client.render.fog;
+
+import su.divan2000.veila.client.gl.FullscreenQuad;
+import su.divan2000.veila.client.gl.GLProgram;
+import su.divan2000.veila.client.gl.GLShader;
+import su.divan2000.veila.client.gl.ResourceUtil;
+
+import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL12;
+import org.lwjgl.opengl.GL13;
+import org.lwjgl.opengl.GL20;
+import org.lwjgl.opengl.GL30;
+
+import java.nio.ByteBuffer;
+
+import static org.lwjgl.opengl.GL11.GL_TEXTURE_BINDING_2D;
+import static org.lwjgl.opengl.GL12.GL_TEXTURE_BINDING_3D;
+
+public final class FogSimulationShader {
+
+    private static GLProgram program;
+    private static int fbo = -1;
+
+    private static int worldInfoSamplerLocation;
+    private static int fogReadSamplerLocation;
+    private static int globalEmissionMultiplierLocation;
+    private static int globalAbsorptionMultiplierLocation;
+    private static int globalDecayLocation;
+    private static int diffusionRateLocation;
+    private static int upDiffusionLocation;
+    private static int downDiffusionLocation;
+    private static int horizontalDiffusionLocation;
+    private static int voxelSizeLocation;
+    private static int currentZLocation;
+
+    private FogSimulationShader() {
+    }
+
+    public static void init() {
+        if (program != null) return;
+
+        FullscreenQuad.init();
+
+        GLShader vertex = new GLShader(
+                GL20.GL_VERTEX_SHADER,
+                ResourceUtil.load("shaders/fullscreen.vert")
+        );
+
+        GLShader fragment = new GLShader(
+                GL20.GL_FRAGMENT_SHADER,
+                ResourceUtil.load("shaders/sim.frag")
+        );
+
+        program = new GLProgram(vertex, fragment);
+
+        worldInfoSamplerLocation = program.uniform("WorldInfoSampler");
+        fogReadSamplerLocation = program.uniform("FogReadSampler");
+        globalEmissionMultiplierLocation = program.uniform("GlobalEmissionMultiplier");
+        globalAbsorptionMultiplierLocation = program.uniform("GlobalAbsorptionMultiplier");
+        globalDecayLocation = program.uniform("GlobalDecay");
+        diffusionRateLocation = program.uniform("DiffusionRate");
+        upDiffusionLocation = program.uniform("UpDiffusion");
+        downDiffusionLocation = program.uniform("DownDiffusion");
+        horizontalDiffusionLocation = program.uniform("HorizontalDiffusion");
+        voxelSizeLocation = program.uniform("VoxelSize");
+        currentZLocation = program.uniform("CurrentZ");
+
+        fbo = GL30.glGenFramebuffers();
+
+        vertex.delete();
+        fragment.delete();
+    }
+
+    public static void simulate(
+            float globalEmissionMultiplier,
+            float globalAbsorptionMultiplier,
+            float globalDecay,
+            float diffusionRate,
+            float upDiffusion,
+            float downDiffusion,
+            float horizontalDiffusion
+    ) {
+        if (program == null) return;
+
+        int fogRead = FogDensityTextures.getReadTexture();
+        int fogWrite = FogDensityTextures.getWriteTexture();
+        int worldInfo = FogWorldVolume.getTexture();
+
+        // ========================================
+        // ПОЛНОЕ СОХРАНЕНИЕ СОСТОЯНИЯ OPENGL
+        // ========================================
+
+        // FBO и viewport
+        int previousFBO = GL11.glGetInteger(GL30.GL_FRAMEBUFFER_BINDING);
+        int[] previousViewport = new int[4];
+        GL11.glGetIntegerv(GL11.GL_VIEWPORT, previousViewport);
+
+        // Program
+        int previousProgram = GL11.glGetInteger(GL20.GL_CURRENT_PROGRAM);
+
+        // VAO
+        int previousVAO = GL11.glGetInteger(GL30.GL_VERTEX_ARRAY_BINDING);
+
+        // Активный текстурный юнит
+        int previousActiveTexture = GL11.glGetInteger(GL13.GL_ACTIVE_TEXTURE);
+
+        // Привязки текстур для юнитов 0 и 1 (2D и 3D)
+        GL13.glActiveTexture(GL13.GL_TEXTURE0);
+        int previousTex0_2D = GL11.glGetInteger(GL_TEXTURE_BINDING_2D);
+        int previousTex0_3D = GL11.glGetInteger(GL_TEXTURE_BINDING_3D);
+
+        GL13.glActiveTexture(GL13.GL_TEXTURE1);
+        int previousTex1_2D = GL11.glGetInteger(GL_TEXTURE_BINDING_2D);
+        int previousTex1_3D = GL11.glGetInteger(GL_TEXTURE_BINDING_3D);
+
+        // Blend state (на всякий случай)
+        boolean previousBlend = GL11.glIsEnabled(GL11.GL_BLEND);
+        boolean previousDepthTest = GL11.glIsEnabled(GL11.GL_DEPTH_TEST);
+        boolean previousCullFace = GL11.glIsEnabled(GL11.GL_CULL_FACE);
+
+        // Color mask
+        ByteBuffer previousColorMask = org.lwjgl.BufferUtils.createByteBuffer(4);
+        GL11.glGetBooleanv(GL11.GL_COLOR_WRITEMASK, previousColorMask);
+
+        // Depth mask
+        boolean previousDepthMask = GL11.glGetBoolean(GL11.GL_DEPTH_WRITEMASK);
+
+        // ========================================
+        // НАСТРОЙКА СОСТОЯНИЯ ДЛЯ СИМУЛЯЦИИ
+        // ========================================
+
+        // Отключаем всё лишнее
+        GL11.glDisable(GL11.GL_BLEND);
+        GL11.glDisable(GL11.GL_DEPTH_TEST);
+        GL11.glDisable(GL11.GL_CULL_FACE);
+        GL11.glColorMask(true, true, true, true);
+        GL11.glDepthMask(false);
+
+        // Привязываем framebuffer
+        GL30.glBindFramebuffer(GL30.GL_FRAMEBUFFER, fbo);
+
+        // Настраиваем viewport
+        GL11.glViewport(0, 0, FogWorldVolume.SIZE_X, FogWorldVolume.SIZE_Y);
+
+        // Привязываем программу
+        program.bind();
+
+        // Привязываем текстуры
+        GL13.glActiveTexture(GL13.GL_TEXTURE0);
+        GL11.glBindTexture(GL12.GL_TEXTURE_3D, worldInfo);
+        GL20.glUniform1i(worldInfoSamplerLocation, 0);
+
+        GL13.glActiveTexture(GL13.GL_TEXTURE1);
+        GL11.glBindTexture(GL12.GL_TEXTURE_3D, fogRead);
+        GL20.glUniform1i(fogReadSamplerLocation, 1);
+
+        // Устанавливаем параметры
+        GL20.glUniform1f(globalEmissionMultiplierLocation, globalEmissionMultiplier);
+        GL20.glUniform1f(globalAbsorptionMultiplierLocation, globalAbsorptionMultiplier);
+        GL20.glUniform1f(globalDecayLocation, globalDecay);
+        GL20.glUniform1f(diffusionRateLocation, diffusionRate);
+        GL20.glUniform1f(upDiffusionLocation, upDiffusion);
+        GL20.glUniform1f(downDiffusionLocation, downDiffusion);
+        GL20.glUniform1f(horizontalDiffusionLocation, horizontalDiffusion);
+        GL20.glUniform3f(voxelSizeLocation,
+                1.0f / FogWorldVolume.SIZE_X,
+                1.0f / FogWorldVolume.SIZE_Y,
+                1.0f / FogWorldVolume.SIZE_Z
+        );
+
+        // ========================================
+        // РЕНДЕРИНГ
+        // ========================================
+
+        for (int z = 0; z < FogWorldVolume.SIZE_Z; z++) {
+            GL30.glFramebufferTexture3D(
+                    GL30.GL_FRAMEBUFFER,
+                    GL30.GL_COLOR_ATTACHMENT0,
+                    GL12.GL_TEXTURE_3D,
+                    fogWrite,
+                    0,
+                    z
+            );
+
+            GL20.glUniform1f(currentZLocation, (float) z / FogWorldVolume.SIZE_Z);
+
+            FullscreenQuad.draw();
+        }
+
+        // ========================================
+        // ПОЛНОЕ ВОССТАНОВЛЕНИЕ СОСТОЯНИЯ
+        // ========================================
+
+        // Отвязываем программу
+        GL20.glUseProgram(previousProgram);
+
+        // Отвязываем FBO
+        GL30.glBindFramebuffer(GL30.GL_FRAMEBUFFER, previousFBO);
+
+        // Восстанавливаем viewport
+        GL11.glViewport(previousViewport[0], previousViewport[1],
+                previousViewport[2], previousViewport[3]);
+
+        // Восстанавливаем VAO
+        GL30.glBindVertexArray(previousVAO);
+
+        // Восстанавливаем текстуры
+        GL13.glActiveTexture(GL13.GL_TEXTURE0);
+        GL11.glBindTexture(GL11.GL_TEXTURE_2D, previousTex0_2D);
+        GL11.glBindTexture(GL12.GL_TEXTURE_3D, previousTex0_3D);
+
+        GL13.glActiveTexture(GL13.GL_TEXTURE1);
+        GL11.glBindTexture(GL11.GL_TEXTURE_2D, previousTex1_2D);
+        GL11.glBindTexture(GL12.GL_TEXTURE_3D, previousTex1_3D);
+
+        // Восстанавливаем активный текстурный юнит
+        GL13.glActiveTexture(previousActiveTexture);
+
+        // Восстанавливаем blend/depth/cull
+        if (previousBlend) GL11.glEnable(GL11.GL_BLEND);
+        else GL11.glDisable(GL11.GL_BLEND);
+
+        if (previousDepthTest) GL11.glEnable(GL11.GL_DEPTH_TEST);
+        else GL11.glDisable(GL11.GL_DEPTH_TEST);
+
+        if (previousCullFace) GL11.glEnable(GL11.GL_CULL_FACE);
+        else GL11.glDisable(GL11.GL_CULL_FACE);
+
+        // Восстанавливаем color mask
+        GL11.glColorMask(
+                previousColorMask.get(0) != 0,
+                previousColorMask.get(1) != 0,
+                previousColorMask.get(2) != 0,
+                previousColorMask.get(3) != 0
+        );
+
+        // Восстанавливаем depth mask
+        GL11.glDepthMask(previousDepthMask);
+
+        // Меняем текстуры местами
+        FogDensityTextures.swap();
+    }
+}

src/client/java/su/divan2000/veila/client/render/fog/FogSystem.java

@@ -28,6 +28,8 @@ public final class FogSystem {
 
         // Всегда обрабатываем изменения блоков
         FogChunkStreamer.processBlockChanges();
+
+        FogSimulationManager.update();
     }
 
     public static void tick() {
@@ -36,6 +38,7 @@ public final class FogSystem {
 
     private static void initialize() {
         FogWorldVolume.init();
+        FogSimulationManager.init();
         initialized = true;
     }
 

src/client/java/su/divan2000/veila/mixin/client/GameRendererMixin.java

@@ -61,6 +61,9 @@ public class GameRendererMixin {
             boolean tick,
             CallbackInfo ci
     ) {
+        net.minecraft.client.MinecraftClient client = net.minecraft.client.MinecraftClient.getInstance();
+        if (client.world != null && client.player != null) {
             FogSystem.beginRender();
         }
     }
+}

src/client/resources/assets/veila/shaders/red.frag

@@ -2,7 +2,7 @@
 
 uniform sampler2D DiffuseSampler;
 uniform sampler2D DepthSampler;
-uniform usampler3D FogVolume;
+uniform sampler3D FogVolume;
 
 uniform mat4 InverseProjection;
 uniform mat4 InverseView;

src/client/resources/assets/veila/shaders/sim.frag

@@ -0,0 +1,191 @@
+#version 150
+
+uniform usampler3D WorldInfoSampler;
+uniform sampler3D FogReadSampler;
+
+uniform float GlobalEmissionMultiplier;
+uniform float GlobalAbsorptionMultiplier;
+uniform float GlobalDecay;
+uniform float DiffusionRate;
+uniform float UpDiffusion;
+uniform float DownDiffusion;
+uniform float HorizontalDiffusion;
+
+uniform vec3 VoxelSize;
+uniform float CurrentZ;
+
+in vec2 texCoord;
+out vec4 FragColor;
+
+// Получение эмиссии из magnitude
+float getEmission(uint magnitude, bool isAbsorber) {
+    if (isAbsorber || magnitude == 0u) return 0.0;
+    return float(magnitude) / 63.0 * 0.05;
+}
+
+// Получение абсорбции из magnitude
+float getAbsorption(uint magnitude, bool isAbsorber) {
+    if (!isAbsorber || magnitude == 0u) return 0.0;
+    return float(magnitude) / 63.0 * 0.05;
+}
+
+void main() {
+    vec3 uv = vec3(texCoord, CurrentZ);
+
+    // Читаем упакованное значение
+    uint packedSelf = texture(WorldInfoSampler, uv).r;
+
+    // Распаковываем через арифметику (битовые операции не доступны в GLSL 1.50)
+    bool selfSolid = (packedSelf >= 128u);
+    uint tempSelf = packedSelf;
+    if (selfSolid) tempSelf -= 128u;
+
+    bool selfIsAbsorber = (tempSelf >= 64u);
+    if (selfIsAbsorber) tempSelf -= 64u;
+
+    uint selfMagnitude = tempSelf;
+
+    // Если solid, плотность всегда 0
+    if (selfSolid) {
+        FragColor = vec4(0.0);
+        return;
+    }
+
+    // Читаем текущую плотность
+    float fogOld = texture(FogReadSampler, uv).r;
+    float fogNew = fogOld;
+
+    // === 1. Emission ===
+    float emission = 0.0;
+
+    // Эмиссия от текущего вокселя (если non-solid источник)
+    emission += getEmission(selfMagnitude, selfIsAbsorber) * GlobalEmissionMultiplier;
+
+    // Эмиссия от соседних solid источников
+    // Инициализируем массив через индексы (так надежнее в GLSL 1.50)
+    vec3 offsets[6];
+    offsets[0] = vec3(VoxelSize.x, 0.0, 0.0);   // +X
+    offsets[1] = vec3(-VoxelSize.x, 0.0, 0.0);  // -X
+    offsets[2] = vec3(0.0, VoxelSize.y, 0.0);   // +Y (Up)
+    offsets[3] = vec3(0.0, -VoxelSize.y, 0.0);  // -Y (Down)
+    offsets[4] = vec3(0.0, 0.0, VoxelSize.z);   // +Z
+    offsets[5] = vec3(0.0, 0.0, -VoxelSize.z);  // -Z
+
+    for (int i = 0; i < 6; i++) {
+        vec3 neighborUV = uv + offsets[i];
+        uint packedNeighbor = texture(WorldInfoSampler, neighborUV).r;
+
+        // Распаковываем соседа
+        bool neighborSolid = (packedNeighbor >= 128u);
+        uint tempNeighbor = packedNeighbor;
+        if (neighborSolid) tempNeighbor -= 128u;
+
+        bool neighborIsAbsorber = (tempNeighbor >= 64u);
+        if (neighborIsAbsorber) tempNeighbor -= 64u;
+
+        uint neighborMagnitude = tempNeighbor;
+
+        // Solid источник влияет на non-solid соседей
+        if (neighborSolid) {
+            emission += getEmission(neighborMagnitude, neighborIsAbsorber) * GlobalEmissionMultiplier;
+        }
+    }
+
+    fogNew += emission;
+
+    // === 2. Absorption ===
+    float absorption = 0.0;
+
+    // Поглощение от текущего вокселя (если non-solid поглотитель)
+    absorption += fogOld * getAbsorption(selfMagnitude, selfIsAbsorber) * GlobalAbsorptionMultiplier;
+
+    // Поглощение от соседних solid поглотителей
+    for (int i = 0; i < 6; i++) {
+        vec3 neighborUV = uv + offsets[i];
+        uint packedNeighbor = texture(WorldInfoSampler, neighborUV).r;
+
+        // Распаковываем соседа
+        bool neighborSolid = (packedNeighbor >= 128u);
+        uint tempNeighbor = packedNeighbor;
+        if (neighborSolid) tempNeighbor -= 128u;
+
+        bool neighborIsAbsorber = (tempNeighbor >= 64u);
+        if (neighborIsAbsorber) tempNeighbor -= 64u;
+
+        uint neighborMagnitude = tempNeighbor;
+
+        // Solid поглотитель влияет на non-solid соседей
+        if (neighborSolid) {
+            absorption += fogOld * getAbsorption(neighborMagnitude, neighborIsAbsorber) * GlobalAbsorptionMultiplier;
+        }
+    }
+
+    fogNew -= absorption;
+
+    // === 3. Diffusion ===
+    float diffusion = 0.0;
+
+    // +X (right)
+    vec3 uvRight = uv + offsets[0];
+    uint packedRight = texture(WorldInfoSampler, uvRight).r;
+    bool rightSolid = (packedRight >= 128u);
+    if (!rightSolid) {
+        float fogRight = texture(FogReadSampler, uvRight).r;
+        diffusion += (fogRight - fogOld) * HorizontalDiffusion * DiffusionRate;
+    }
+
+    // -X (left)
+    vec3 uvLeft = uv + offsets[1];
+    uint packedLeft = texture(WorldInfoSampler, uvLeft).r;
+    bool leftSolid = (packedLeft >= 128u);
+    if (!leftSolid) {
+        float fogLeft = texture(FogReadSampler, uvLeft).r;
+        diffusion += (fogLeft - fogOld) * HorizontalDiffusion * DiffusionRate;
+    }
+
+    // +Y (up)
+    vec3 uvUp = uv + offsets[2];
+    uint packedUp = texture(WorldInfoSampler, uvUp).r;
+    bool upSolid = (packedUp >= 128u);
+    if (!upSolid) {
+        float fogUp = texture(FogReadSampler, uvUp).r;
+        diffusion += (fogUp - fogOld) * UpDiffusion * DiffusionRate;
+    }
+
+    // -Y (down)
+    vec3 uvDown = uv + offsets[3];
+    uint packedDown = texture(WorldInfoSampler, uvDown).r;
+    bool downSolid = (packedDown >= 128u);
+    if (!downSolid) {
+        float fogDown = texture(FogReadSampler, uvDown).r;
+        diffusion += (fogDown - fogOld) * DownDiffusion * DiffusionRate;
+    }
+
+    // +Z
+    vec3 uvFront = uv + offsets[4];
+    uint packedFront = texture(WorldInfoSampler, uvFront).r;
+    bool frontSolid = (packedFront >= 128u);
+    if (!frontSolid) {
+        float fogFront = texture(FogReadSampler, uvFront).r;
+        diffusion += (fogFront - fogOld) * HorizontalDiffusion * DiffusionRate;
+    }
+
+    // -Z
+    vec3 uvBack = uv + offsets[5];
+    uint packedBack = texture(WorldInfoSampler, uvBack).r;
+    bool backSolid = (packedBack >= 128u);
+    if (!backSolid) {
+        float fogBack = texture(FogReadSampler, uvBack).r;
+        diffusion += (fogBack - fogOld) * HorizontalDiffusion * DiffusionRate;
+    }
+
+    fogNew += diffusion;
+
+    // === 4. Global Decay ===
+    fogNew -= fogOld * GlobalDecay;
+
+    // === 5. Clamp ===
+    fogNew = clamp(fogNew, 0.0, 1.0);
+
+    FragColor = vec4(fogNew, 0.0, 0.0, 1.0);
+}