diff --git a/.gitignore b/.gitignore
index 4e9f795..063c9c0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -30,6 +30,7 @@
 
 !/engine/project.godot
 !/engine/icon.svg
+!/engine/environment.tscn
 
 # /engine/bin
 !/engine/bin
diff --git a/configure.ac b/configure.ac
index e8a28de..36d0adb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -21,9 +21,11 @@ AM_CONFIG_HEADER([src/config.h])
 AC_CONFIG_MACRO_DIR([m4
                     ])
 
+# Use libtool.
 AC_PROG_LIBTOOL
 AC_PROG_INSTALL
 
+# Prefer shared libraries.
 AC_ENABLE_SHARED
 AC_DISABLE_STATIC
 
diff --git a/engine/environment.tscn b/engine/environment.tscn
new file mode 100644
index 0000000..d244f47
--- /dev/null
+++ b/engine/environment.tscn
@@ -0,0 +1,3 @@
+[gd_scene format=3 uid="uid://b827xc3j75sb6"]
+
+[node name="Node3D" type="Node3D"]
diff --git a/src/Makefile.am b/src/Makefile.am
index dba315a..6a29f83 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -5,7 +5,9 @@
 #__top_builddir__bin_rtr_SOURCES = main.c # Sources
 lib_LTLIBRARIES = librtr.la
 librtr_la_SOURCES = main.c
-librtr_la_LDFLAGS = -module -avoid-version -export-dynamic
+
+# Compile as shared library.
+librtr_la_LDFLAGS = -module -avoid-version -export-dynamic -no-undefined
 
 #bin_PROGRAMS = rtr
 #rtr_CFLAGS = -DBUILD -c -fPIC -shared # Define BUILD and output shared.