Update Examples

mesh_import/README.md

@@ -0,0 +1,3 @@
+Imports a .obj mesh at runtime with physics.
+
+- Click the canvas to spawn the imported mesh; it drops under physics.

mesh_import/Sources/lnx/ImportMesh.hx

@@ -28,6 +28,7 @@ class ImportMesh extends iron.Trait {
 
 			var rawmeshData:TMeshData = {
 				name: "BoxMesh",
+				sorting_index: 0,
 				vertex_arrays: [pos, nor],
 				index_arrays: [ind],
 				// Usable to scale positions over the (-1, 1) range