diff --git a/modules/world-core/src/block_registry_tests.zig b/modules/world-core/src/block_registry_tests.zig
index 1ed7818c..31eec7f7 100644
--- a/modules/world-core/src/block_registry_tests.zig
+++ b/modules/world-core/src/block_registry_tests.zig
@@ -181,6 +181,28 @@ test "core natural block pack registry properties" {
     try testing.expectEqual(block_registry.RenderPass.solid, block_registry.getBlockDefinition(.white_terracotta).render_pass);
 }
 
+test "BlockDefinition.isFullCubeOccluder true for solid cube blocks" {
+    try testing.expect(block_registry.getBlockDefinition(.stone).isFullCubeOccluder());
+    try testing.expect(block_registry.getBlockDefinition(.bedrock).isFullCubeOccluder());
+    try testing.expect(block_registry.getBlockDefinition(.cobblestone).isFullCubeOccluder());
+}
+
+test "BlockDefinition.isFullCubeOccluder false for transparent blocks" {
+    try testing.expect(!block_registry.getBlockDefinition(.glass).isFullCubeOccluder());
+    try testing.expect(!block_registry.getBlockDefinition(.ice).isFullCubeOccluder());
+}
+
+test "BlockDefinition.isFullCubeOccluder false for non-cube shapes" {
+    try testing.expect(!block_registry.getBlockDefinition(.torch).isFullCubeOccluder());
+    try testing.expect(!block_registry.getBlockDefinition(.tall_grass).isFullCubeOccluder());
+    try testing.expect(!block_registry.getBlockDefinition(.vine).isFullCubeOccluder());
+}
+
+test "BlockDefinition.isFullCubeOccluder false for solid but non-cube render shape" {
+    try testing.expect(!block_registry.getBlockDefinition(.stone_slab).isFullCubeOccluder());
+    try testing.expect(!block_registry.getBlockDefinition(.stone_stairs).isFullCubeOccluder());
+}
+
 test "aquatic vegetation blocks use cutout shapes" {
     const seagrass = block_registry.getBlockDefinition(.seagrass);
     try testing.expect(!seagrass.is_solid);
diff --git a/modules/world-meshing/src/meshing/boundary_cross_tests.zig b/modules/world-meshing/src/meshing/boundary_cross_tests.zig
new file mode 100644
index 00000000..7aa11888
--- /dev/null
+++ b/modules/world-meshing/src/meshing/boundary_cross_tests.zig
@@ -0,0 +1,56 @@
+const std = @import("std");
+const testing = std.testing;
+const boundary = @import("boundary.zig");
+const NeighborChunks = boundary.NeighborChunks;
+const Chunk = @import("world-core").Chunk;
+
+test "getBlockCross cross-chunk east neighbor returns neighbor block" {
+    var chunk = Chunk.init(0, 0);
+    var east = Chunk.init(1, 0);
+    east.setBlock(0, 64, 8, .glowstone);
+    const neighbors = NeighborChunks{ .east = &east };
+    try testing.expectEqual(.glowstone, boundary.getBlockCross(&chunk, neighbors, 16, 64, 8));
+}
+
+test "getBlockCross cross-chunk north neighbor returns neighbor block" {
+    var chunk = Chunk.init(0, 1);
+    var north = Chunk.init(0, 0);
+    north.setBlock(8, 64, 15, .water);
+    const neighbors = NeighborChunks{ .north = &north };
+    try testing.expectEqual(.water, boundary.getBlockCross(&chunk, neighbors, 8, 64, -1));
+}
+
+test "getBlockCross null neighbor returns air" {
+    var chunk = Chunk.init(0, 0);
+    try testing.expectEqual(.air, boundary.getBlockCross(&chunk, .empty, 16, 64, 8));
+    try testing.expectEqual(.air, boundary.getBlockCross(&chunk, .empty, -1, 64, 8));
+    try testing.expectEqual(.air, boundary.getBlockCross(&chunk, .empty, 8, 64, 16));
+}
+
+test "getEntranceBounceCross cross-chunk west neighbor returns neighbor value" {
+    var chunk = Chunk.init(1, 0);
+    var west = Chunk.init(0, 0);
+    west.setEntranceBounce(15, 64, 8, 5);
+    const neighbors = NeighborChunks{ .west = &west };
+    try testing.expectEqual(@as(u4, 5), boundary.getEntranceBounceCross(&chunk, neighbors, -1, 64, 8));
+}
+
+test "getEntranceBounceCross out of Y range returns zero" {
+    var chunk = Chunk.init(0, 0);
+    try testing.expectEqual(@as(u4, 0), boundary.getEntranceBounceCross(&chunk, .empty, 5, -1, 10));
+    try testing.expectEqual(@as(u4, 0), boundary.getEntranceBounceCross(&chunk, .empty, 5, 256, 10));
+}
+
+test "getEntranceDirCross cross-chunk south neighbor returns neighbor value" {
+    var chunk = Chunk.init(0, 0);
+    var south = Chunk.init(0, 1);
+    south.setEntranceDir(8, 64, 0, 99);
+    const neighbors = NeighborChunks{ .south = &south };
+    try testing.expectEqual(@as(u8, 99), boundary.getEntranceDirCross(&chunk, neighbors, 8, 64, 16));
+}
+
+test "getEntranceDirCross null neighbor on boundary returns zero" {
+    var chunk = Chunk.init(0, 0);
+    try testing.expectEqual(@as(u8, 0), boundary.getEntranceDirCross(&chunk, .empty, 16, 64, 8));
+    try testing.expectEqual(@as(u8, 0), boundary.getEntranceDirCross(&chunk, .empty, -1, 64, 8));
+}
diff --git a/modules/world-meshing/src/root.zig b/modules/world-meshing/src/root.zig
index 00af1266..1ae4802f 100644
--- a/modules/world-meshing/src/root.zig
+++ b/modules/world-meshing/src/root.zig
@@ -13,6 +13,7 @@ pub const meshing = struct {
     pub const biome_color_sampler = @import("meshing/biome_color_sampler.zig");
     pub const boundary = @import("meshing/boundary.zig");
     pub const boundary_tests = @import("meshing/boundary_tests.zig");
+    pub const boundary_cross_tests = @import("meshing/boundary_cross_tests.zig");
     pub const cross_mesher = @import("meshing/cross_mesher.zig");
     pub const custom_mesh_mesher = @import("meshing/custom_mesh_mesher.zig");
     pub const greedy_mesher = @import("meshing/greedy_mesher.zig");
diff --git a/src/tests.zig b/src/tests.zig
index c4bb6aaa..374fd1ce 100644
--- a/src/tests.zig
+++ b/src/tests.zig
@@ -95,6 +95,7 @@ test {
     _ = @import("world-meshing").chunk_storage_interface_tests;
     _ = @import("world-core").biome_and_block_tests;
     _ = @import("world-core").packed_light_tests;
+    _ = @import("world-meshing").meshing.boundary_cross_tests;
     _ = @import("world-meshing").meshing.boundary_tests;
     _ = @import("world-core").world_coord_tests;
     _ = @import("world-core").world_block_fill_tests;