Fix refraction and material transitions.

chunky/src/java/se/llbit/chunky/block/minecraft/Air.java

@@ -29,5 +29,6 @@ private Air() {
     solid = false;
     opaque = false;
     invisible = true;
+    refractive = true;
   }
 }

chunky/src/java/se/llbit/chunky/model/AnimatedQuadModel.java

@@ -3,6 +3,7 @@
 import se.llbit.chunky.plugin.PluginApi;
 import se.llbit.chunky.renderer.scene.Scene;
 import se.llbit.chunky.resources.AnimatedTexture;
+import se.llbit.chunky.world.Material;
 import se.llbit.math.Quad;
 import se.llbit.math.Ray;
 import se.llbit.math.Vector3;
@@ -42,7 +43,7 @@ public boolean intersect(Ray ray, Scene scene) {
     Quad[] quads = getQuads();
     AnimatedTexture[] textures = getTextures();
     Tint[] tintedQuads = getTints();
-
+    Material mat = ray.getCurrentMaterial();
     // The animation frame to use
     int j = (int) (scene.getAnimationTime() * animationMode.framerate);
     if (animationMode.positional) {
@@ -58,11 +59,11 @@ public boolean intersect(Ray ray, Scene scene) {
       Quad quad = quads[i];
       if (quad.intersect(ray)) {
         float[] c = textures[i].getColor(ray.u, ray.v, j);
-        if (c[3] > Ray.EPSILON) {
+        if (c[3] > Ray.EPSILON || mat.refractive) {
           tint = tintedQuads == null ? Tint.NONE : tintedQuads[i];
           color = c;
           ray.t = ray.tNext;
-          if (quad.doubleSided)
+          if (quad.doubleSided || mat.refractive)
             ray.orientNormal(quad.n);
           else
             ray.setNormal(quad.n);

chunky/src/java/se/llbit/chunky/model/QuadModel.java

@@ -23,6 +23,7 @@
 import se.llbit.chunky.plugin.PluginApi;
 import se.llbit.chunky.renderer.scene.Scene;
 import se.llbit.chunky.resources.Texture;
+import se.llbit.chunky.world.Material;
 import se.llbit.math.Quad;
 import se.llbit.math.Ray;
 import se.llbit.math.Vector3;
@@ -114,18 +115,19 @@ public boolean intersect(Ray ray, Scene scene) {
     Quad[] quads = getQuads();
     Texture[] textures = getTextures();
     Tint[] tintedQuads = getTints();
+    Material mat = ray.getCurrentMaterial();
 
     float[] color = null;
     Tint tint = Tint.NONE;
     for (int i = 0; i < quads.length; ++i) {
       Quad quad = quads[i];
       if (quad.intersect(ray)) {
         float[] c = textures[i].getColor(ray.u, ray.v);
-        if (c[3] > Ray.EPSILON) {
+        if (c[3] > Ray.EPSILON || mat.refractive) {
           tint = tintedQuads == null ? Tint.NONE : tintedQuads[i];
           color = c;
           ray.t = ray.tNext;
-          if (quad.doubleSided)
+          if (quad.doubleSided || mat.refractive)
             ray.orientNormal(quad.n);
           else
             ray.setNormal(quad.n);

chunky/src/java/se/llbit/chunky/renderer/scene/Scene.java

@@ -345,8 +345,8 @@ public Scene() {
     branchCount = PersistentSettings.getBranchCountDefault();
 
     palette = new BlockPalette();
-    worldOctree = new Octree(octreeImplementation, 1);
-    waterOctree = new Octree(octreeImplementation, 1);
+    worldOctree = new Octree(octreeImplementation, 1, Octree.OctreeType.WORLD);
+    waterOctree = new Octree(octreeImplementation, 1, Octree.OctreeType.WATER);
     emitterGrid = null;
   }
 
@@ -723,7 +723,7 @@ private boolean worldIntersection(Ray ray) {
     } else {
       r = new Ray(start);
       r.setCurrentMaterial(start.getPrevMaterial(), start.getPrevData());
-      if (waterOctree.enterBlock(this, r, palette) && r.distance < ray.t) {
+      if (waterOctree.enterBlock(this, r, palette) && r.distance < ray.t + Ray.EPSILON) {
         ray.t = r.distance;
         ray.setNormal(r.getNormal());
         ray.color.set(r.color);
@@ -803,8 +803,8 @@ public synchronized void loadChunks(TaskTracker taskTracker, World world, Collec
 
       // Create new octree to fit all chunks.
       palette = new BlockPalette();
-      worldOctree = new Octree(octreeImplementation, requiredDepth);
-      waterOctree = new Octree(octreeImplementation, requiredDepth);
+      worldOctree = new Octree(octreeImplementation, requiredDepth, Octree.OctreeType.WORLD);
+      waterOctree = new Octree(octreeImplementation, requiredDepth, Octree.OctreeType.WATER);
 
       grassTexture = biomeStructureFactory.create();
       foliageTexture = biomeStructureFactory.create();
@@ -2202,6 +2202,12 @@ private synchronized boolean loadOctree(SceneIOProvider ioContext, TaskTracker t
           // this dump is so old that it doesn't contain a water texture (Chunky 2.3.0, #691)
           waterTexture = BiomeStructure.get(this.biomeStructureImplementation).create();
         }
+        if (worldOctree.type == null) {
+          worldOctree.type = Octree.OctreeType.WORLD;
+        }
+        if (waterOctree.type == null) {
+          waterOctree.type = Octree.OctreeType.WATER;
+        }
         palette = data.palette;
         palette.applyMaterials();
         Log.info("Octree loaded");

chunky/src/java/se/llbit/math/Octree.java

@@ -244,11 +244,26 @@ public int getData() {
     }
   }
 
+  /** The type of Octree, used to adjust intersection code based on contents*/
+  public enum OctreeType {
+    /**
+     * Contains all world geometry excluding water, water is removed from water logged blocks
+     * and full water blocks are replaced with air
+     */
+    WORLD,
+    /**
+     * Contains all the water geometry only, other blocks are air
+     */
+    WATER
+  }
+
   /**
    * Timestamp of last serialization.
    */
   private long timestamp = 0;
 
+  public OctreeType type;
+
   private OctreeImplementation implementation;
 
   /**
@@ -257,9 +272,10 @@ public int getData() {
    *
    * @param octreeDepth The number of levels in the Octree.
    */
-  public Octree(String impl, int octreeDepth) {
+  public Octree(String impl, int octreeDepth, OctreeType type) {
     Log.infof("Building new octree (%s)", impl);
     implementation = getImplementationFactory(impl).create(octreeDepth);
+    this.type = type;
   }
 
   protected Octree(OctreeImplementation impl) {
@@ -484,6 +500,8 @@ public boolean enterBlock(Scene scene, Ray ray, BlockPalette palette) {
     int depth = implementation.getDepth();
 
     double distance = 0;
+    //tread air as a null block depending on octreetype and were we are in the trace
+    boolean includeAir = this.type == OctreeType.WORLD && !ray.getPrevMaterial().isWater();
 
     // floating point division are slower than multiplication so we cache them
     // We also try to limit the number of time the ray origin is updated
@@ -539,9 +557,14 @@ public boolean enterBlock(Scene scene, Ray ray, BlockPalette palette) {
         ray.distance += distance;
         distance = 0;
         if (currentBlock.intersect(ray, scene)) {
-          if (prevBlock != currentBlock)
+          if (prevBlock != currentBlock) { //|| (currentBlock.refractive)) {
+            //for things like glass panes coerce the current mat to be air or water
+            // TODO testing
+            if (currentBlock.refractive) {
+              //ray.setCurrentMaterial(currentBlock.waterlogged ? Water.INSTANCE : Air.INSTANCE);
+            }
             return true;
-
+          }
           ray.o.scaleAdd(Ray.OFFSET, ray.d);
           offsetX = -ray.o.x * invDx;
           offsetY = -ray.o.y * invDy;
@@ -556,7 +579,7 @@ public boolean enterBlock(Scene scene, Ray ray, BlockPalette palette) {
           offsetZ = -ray.o.z * invDz;
           continue;
         }
-      } else if (!currentBlock.isSameMaterial(prevBlock) && currentBlock != Air.INSTANCE) {
+      } else if (!currentBlock.isSameMaterial(prevBlock) && (currentBlock != Air.INSTANCE || includeAir)) {
         // Origin and distance of ray need to be updated
         ray.o.scaleAdd(distance, ray.d);
         ray.distance += distance;

chunky/src/java/se/llbit/math/Quad.java

@@ -158,14 +158,14 @@ public void sample(Vector3 loc, Random rand) {
    */
   public boolean intersect(Ray ray) {
     double u, v;
-
+    Material mat = ray.getCurrentMaterial();
     double ix = ray.o.x - QuickMath.floor(ray.o.x + ray.d.x * Ray.OFFSET);
     double iy = ray.o.y - QuickMath.floor(ray.o.y + ray.d.y * Ray.OFFSET);
     double iz = ray.o.z - QuickMath.floor(ray.o.z + ray.d.z * Ray.OFFSET);
 
     // Test that the ray is heading toward the plane of this quad.
     double denom = ray.d.dot(n);
-    if (denom < -Ray.EPSILON || (doubleSided && denom > Ray.EPSILON)) {
+    if (denom < -Ray.EPSILON || ((doubleSided || mat.refractive) && denom > Ray.EPSILON)) {
 
       // Test for intersection with the plane at origin.
       double t = -(ix * n.x + iy * n.y + iz * n.z + d) / denom;