add falling_block entity

res/content/base/scripts/sand.lua

@@ -0,0 +1,14 @@
+local function update(x, y, z)
+    if block.is_replaceable_at(x, y-1, z) then
+        entities.spawn("base:falling_block", {x+0.5, y+0.5, z+0.5}, {block='base:sand'})
+        block.set(x, y, z, 0)
+    end
+end
+
+function on_update(x, y, z)
+    update(x, y, z)
+end
+
+function on_placed(x, y, z)
+    update(x, y, z)
+end