Swap chunk-scan direction for future stuff :)

BlueMapCore/src/main/java/de/bluecolored/bluemap/core/map/hires/HiresModelRenderer.java

@@ -78,7 +78,7 @@ public void render(World world, Vector3i modelMin, Vector3i modelMax, TileModel
                     minY = Math.max(min.getY(), chunk.getMinY(x, z));
                     maxY = Math.min(max.getY(), chunk.getMaxY(x, z));
 
-                    for (y = minY; y <= maxY; y++) {
+                    for (y = maxY; y >= minY; y--) {
                         block.set(x, y, z);
                         if (!block.isInsideRenderBounds()) continue;
 
@@ -87,17 +87,7 @@ public void render(World world, Vector3i modelMin, Vector3i modelMax, TileModel
                         modelFactory.render(block, blockModel, blockColor);
 
                         //update topBlockLight
-                        if (
+                        topBlockLight = Math.max(topBlockLight, block.getBlockLightLevel() * (1 - columnColor.a));
-                                y >= renderSettings.getRemoveCavesBelowY() ||
-                                (renderSettings.isCaveDetectionUsesBlockLight() ? block.getBlockLightLevel() : block.getSunLightLevel()) > 0
-                        ) {
-                            if (blockColor.a > 0) {
-                                topBlockLight = Math.floor(topBlockLight * (1 - blockColor.a));
-                            }
-                            topBlockLight = Math.max(topBlockLight, block.getBlockLightLevel());
-                        } else {
-                            topBlockLight = 0;
-                        }
 
                         // skip empty blocks
                         if (blockModel.getSize() <= 0) continue;
@@ -107,9 +97,11 @@ public void render(World world, Vector3i modelMin, Vector3i modelMax, TileModel
 
                         //update color and height (only if not 100% translucent)
                         if (blockColor.a > 0) {
-                            maxHeight = y;
+                            if (maxHeight < y) maxHeight = y;
-                            columnColor.overlay(blockColor.premultiplied());
+                            columnColor.underlay(blockColor.premultiplied());
                         }
+
+                        //if (blockColor.a > 0.999 && block.getProperties().isCulling()) break;
                     }
                 }
 

BlueMapCore/src/main/java/de/bluecolored/bluemap/core/map/hires/blockmodel/ResourceModelBuilder.java

@@ -193,7 +193,17 @@ private void createElementFace(Element element, Direction faceDir, VectorM3f c0,
                 (renderSettings.isCaveDetectionUsesBlockLight() ? Math.max(blockLight, sunLight) : sunLight) == 0
         ) return;
 
+        // calculate faceRotationVector
+        faceRotationVector.set(
+                faceDirVector.getX(),
+                faceDirVector.getY(),
+                faceDirVector.getZ()
+        );
+        faceRotationVector.rotateAndScale(element.getRotation().getMatrix());
+        makeRotationRelative(faceRotationVector);
+
         // face culling
+        //if (faceRotationVector.y < 0.01) return;
         if (face.getCullface() != null) {
             ExtendedBlock<?> b = getRotationRelativeBlock(face.getCullface());
             BlockProperties p = b.getProperties();
@@ -315,14 +325,6 @@ private void createElementFace(Element element, Direction faceDir, VectorM3f c0,
         tileModel.setAOs(face2, ao0, ao2, ao3);
 
         //if is top face set model-color
-        faceRotationVector.set(
-                faceDirVector.getX(),
-                faceDirVector.getY(),
-                faceDirVector.getZ()
-        );
-        faceRotationVector.rotateAndScale(element.getRotation().getMatrix());
-        makeRotationRelative(faceRotationVector);
-
         float a = faceRotationVector.y;
         if (a > 0.01 && texturePath != null) {
             Texture texture = texturePath.getResource(resourcePack::getTexture);

BlueMapCore/src/main/java/de/bluecolored/bluemap/core/util/math/Color.java

@@ -125,6 +125,20 @@ public Color overlay(Color color) {
         return this;
     }
 
+    public Color underlay(Color color) {
+        if (color.a < 1f && !color.premultiplied) throw new IllegalArgumentException("Can only underlay premultiplied colors with alpha!");
+
+        premultiplied();
+
+        float p = 1 - a;
+        this.a = p * color.a + this.a;
+        this.r = p * color.r + this.r;
+        this.g = p * color.g + this.g;
+        this.b = p * color.b + this.b;
+
+        return this;
+    }
+
     public Color flatten() {
         if (this.a == 1f) return this;