diff --git a/.gitignore b/.gitignore
index a6a369a..51d2952 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@
 *.pyc
 *.dxf
 *.stl
+*.d
diff --git a/Makefile b/Makefile
index 1b50f45..c91ea47 100644
--- a/Makefile
+++ b/Makefile
@@ -1,8 +1,11 @@
 INKSCAPE ?= inkscape
 OPENSCAD ?= openscad
+PYTHON ?= python2
+
+PYTHON_CMD := PYTHONPATH="support:$$PYTHONPATH" $(PYTHON)
 
 # Used by dxf_export/main.sh
-export INKSCAPE
+export INKSCAPE OPENSCAD
 
 # Run generate_scad.sh to get the names of all OpenSCAD files that should be generated using that same script.
 GENERATED_FILES := $(addsuffix .scad,$(basename $(shell ./generate_sources.sh)))
@@ -13,34 +16,32 @@ GENERATED_SCAD_FILES := $(filter %.scad, $(GENERATED_FILES))
 SVG_FILES := $(shell find src -name '*.svg') $(GENERATED_SVG_FILES)
 
 # Only OpenSCAD files whose names do not start with `_' are compiled to STL.
-SCAD_FILES := $(shell find src -name '*.scad') $(GENERATED_SCAD_FILES)
-LIBRARY_SCAD_FILES := $(foreach i,$(SCAD_FILES),$(if $(filter _%,$(notdir $(i))),$(i)))  
-COMPILED_SCAD_FILES := $(filter-out $(LIBRARY_SCAD_FILES),$(SCAD_FILES))
+COMPILED_SCAD_FILES := $(foreach i,$(shell find src -name '*.scad') $(GENERATED_SCAD_FILES),$(if $(filter-out _%,$(notdir $(i))),$(i)))
+
+# Makefiles which are generated while compiling to record dependencies.
+DEPENDENCY_FILES := $(patsubst %.scad,%.d,$(COMPILED_SCAD_FILES))
 
 # All files that may be generated from the source files.
 STL_FILES := $(patsubst %.scad,%.stl,$(COMPILED_SCAD_FILES))
 DXF_FILES := $(patsubst %.svg,%.dxf,$(SVG_FILES))
 
 # Everything. Also generates files which aren't compiled to anything else.
-all: $(STL_FILES) $(GENERATED_FILES)
+all: $(GENERATED_FILES) $(DXF_FILES) $(STL_FILES)
 
 # Everything^-1.
 clean:
-	rm -rf $(DXF_FILES) $(STL_FILES) $(GENERATED_FILES)
+	rm -rf $(GENERATED_FILES) $(DXF_FILES) $(STL_FILES) $(DEPENDENCY_FILES)
 
-# Needs to be included after target all has been defined.
--include config.mk
-
-# Assume that any compiled OpenSCAD file may depend on any non-compiled OpenSCAD file in the same directory.
-$(foreach i,$(COMPILED_SCAD_FILES),$(eval $(i): $(filter $(dir $(i))%,$(LIBRARY_SCAD_FILES) $(DXF_FILES))))
+# Include the local configuration file and the dependency files. Needs to be included after the `all' target has been defined.
+-include config.mk $(DEPENDENCY_FILES)
 
 # Rule to convert an SVG file to a DXF file.
 %.dxf: %.svg
-	python2 dxf_export $< $@
+	$(PYTHON_CMD) -m dxf_export $< $@
 
-# Rule to compile an OpenSCAD file to an STL file.
-%.stl: %.scad
-	$(OPENSCAD) -o $@ $<
+# Rule to compile an OpenSCAD file to an STL file. We require all DXF files to exist before an OpenSCAD file can be used to generate an STL file. Additional dependencies are read from the included makefiles generated during compiling.
+%.stl: %.scad  | $(DXF_FILES)
+	$(PYTHON_CMD) -m openscad $< $@ $*.d
 
 # Rule for automaticlaly generated OpenSCAD files.
 $(GENERATED_FILES): generate_sources.sh
diff --git a/src/_settings.scad b/src/_settings.scad
new file mode 100644
index 0000000..1f84b17
--- /dev/null
+++ b/src/_settings.scad
@@ -0,0 +1,2 @@
+plate_height = 2;
+struts_height = 1;
diff --git a/src/example_1.scad b/src/example_1.scad
new file mode 100644
index 0000000..b6e8931
--- /dev/null
+++ b/src/example_1.scad
@@ -0,0 +1,6 @@
+include <_settings.scad>
+
+render(convexity = 10) {
+	linear_extrude(plate_height)
+		import("example.dxf", layer = "text");
+}
diff --git a/src/example_2.scad b/src/example_2.scad
new file mode 100644
index 0000000..2dd57e6
--- /dev/null
+++ b/src/example_2.scad
@@ -0,0 +1,14 @@
+include <_settings.scad>
+
+render(convexity = 10) {
+	union() {
+		linear_extrude(plate_height)
+			difference() {
+				import("example.dxf", layer = "base");
+				import("example.dxf", layer = "text");
+			}
+		
+		linear_extrude(struts_height)
+			import("example.dxf", layer = "struts");
+	}
+}
diff --git a/support/dxf_export/__init__.py b/support/dxf_export/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/dxf_export/__main__.py b/support/dxf_export/__main__.py
similarity index 78%
rename from dxf_export/__main__.py
rename to support/dxf_export/__main__.py
index ea6c7ad..76c2121 100644
--- a/dxf_export/__main__.py
+++ b/support/dxf_export/__main__.py
@@ -1,15 +1,6 @@
-import sys, os, xml.etree.ElementTree, subprocess, tempfile, contextlib, shutil
-import better_dxf_outlines
-
-
-@contextlib.contextmanager
-def TemporaryDirectory():
-	dir = tempfile.mkdtemp()
-	
-	try:
-		yield dir
-	finally:
-		shutil.rmtree(dir)
+import sys, os, xml.etree.ElementTree, shutil
+from lib import util
+from . import better_dxf_outlines
 
 
 def _export_dxf(in_path, out_path):
@@ -28,13 +19,6 @@ def _get_inkscape_layer_count(svg_path):
 	return len(layers)
 
 
-def _command(args):
-	process = subprocess.Popen(args)
-	process.wait()
-	
-	assert not process.returncode
-
-
 def _inkscape(svg_path, verbs):
 	def iter_args():
 		yield os.environ['INKSCAPE']
@@ -45,7 +29,7 @@ def _inkscape(svg_path, verbs):
 		
 		yield svg_path
 	
-	_command(list(iter_args()))
+	util.command(list(iter_args()))
 
 
 def _unfuck_svg_document(temp_svg_path):
@@ -82,7 +66,7 @@ def _unfuck_svg_document(temp_svg_path):
 
 
 def main(in_path, out_path):
-	with TemporaryDirectory() as temp_dir:
+	with util.TemporaryDirectory() as temp_dir:
 		temp_svg_path = os.path.join(temp_dir, 'temp.svg')
 		
 		shutil.copyfile(in_path, temp_svg_path)
diff --git a/dxf_export/better_dxf_outlines.py b/support/dxf_export/better_dxf_outlines.py
similarity index 100%
rename from dxf_export/better_dxf_outlines.py
rename to support/dxf_export/better_dxf_outlines.py
diff --git a/dxf_export/bezmisc.py b/support/dxf_export/bezmisc.py
similarity index 100%
rename from dxf_export/bezmisc.py
rename to support/dxf_export/bezmisc.py
diff --git a/dxf_export/cspsubdiv.py b/support/dxf_export/cspsubdiv.py
similarity index 100%
rename from dxf_export/cspsubdiv.py
rename to support/dxf_export/cspsubdiv.py
diff --git a/dxf_export/cubicsuperpath.py b/support/dxf_export/cubicsuperpath.py
similarity index 100%
rename from dxf_export/cubicsuperpath.py
rename to support/dxf_export/cubicsuperpath.py
diff --git a/dxf_export/dxf_templates.py b/support/dxf_export/dxf_templates.py
similarity index 100%
rename from dxf_export/dxf_templates.py
rename to support/dxf_export/dxf_templates.py
diff --git a/dxf_export/ffgeom.py b/support/dxf_export/ffgeom.py
similarity index 100%
rename from dxf_export/ffgeom.py
rename to support/dxf_export/ffgeom.py
diff --git a/dxf_export/inkex.py b/support/dxf_export/inkex.py
similarity index 100%
rename from dxf_export/inkex.py
rename to support/dxf_export/inkex.py
diff --git a/dxf_export/simplepath.py b/support/dxf_export/simplepath.py
similarity index 100%
rename from dxf_export/simplepath.py
rename to support/dxf_export/simplepath.py
diff --git a/dxf_export/simplestyle.py b/support/dxf_export/simplestyle.py
similarity index 100%
rename from dxf_export/simplestyle.py
rename to support/dxf_export/simplestyle.py
diff --git a/dxf_export/simpletransform.py b/support/dxf_export/simpletransform.py
similarity index 100%
rename from dxf_export/simpletransform.py
rename to support/dxf_export/simpletransform.py
diff --git a/support/lib/__init__.py b/support/lib/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/support/lib/util.py b/support/lib/util.py
new file mode 100644
index 0000000..bede240
--- /dev/null
+++ b/support/lib/util.py
@@ -0,0 +1,36 @@
+import contextlib, subprocess, tempfile, shutil, re, os
+
+
+@contextlib.contextmanager
+def TemporaryDirectory():
+	dir = tempfile.mkdtemp()
+	
+	try:
+		yield dir
+	finally:
+		shutil.rmtree(dir)
+
+
+def command(args):
+	process = subprocess.Popen(args)
+	process.wait()
+	
+	assert not process.returncode
+
+
+def bash_escape_string(string):
+	return "'{}'".format(re.sub("'", "'\"'\"'", string))	
+
+
+def write_file(path, data):
+	temp_path = path + '~'
+	
+	with open(temp_path, 'wb') as file:
+		file.write(data)
+	
+	os.rename(temp_path, path)
+
+
+def read_file(path):
+	with open(path, 'rb') as file:
+		return file.read()
diff --git a/support/openscad/__init__.py b/support/openscad/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/support/openscad/__main__.py b/support/openscad/__main__.py
new file mode 100644
index 0000000..08b2ab6
--- /dev/null
+++ b/support/openscad/__main__.py
@@ -0,0 +1,37 @@
+import os, sys
+from lib import util
+
+
+def _openscad(in_path, out_path, deps_path):
+	util.command([os.environ['OPENSCAD'], '-o', out_path, '-d', deps_path, in_path])
+
+
+def _write_dependencies(path, target, dependencies):
+	util.write_file(path, '{}: {}\n'.format(target, ' '.join(dependencies)).encode())
+
+
+def main(in_path, out_path, deps_path):
+	cwd = os.getcwd()
+	
+	def relpath(path):
+		return os.path.relpath(path, cwd)
+	
+	with util.TemporaryDirectory() as temp_dir:
+		temp_deps_path = os.path.join(temp_dir, 'deps')
+		temp_mk_path = os.path.join(temp_dir, 'mk')
+		temp_files_path = os.path.join(temp_dir, 'files')
+		
+		_openscad(in_path, out_path, temp_deps_path)
+		
+		mk_content = '%:; echo "$@" >> {}'.format(util.bash_escape_string(temp_files_path))
+		
+		util.write_file(temp_mk_path, mk_content.encode())
+		util.command(['make', '-s', '-B', '-f', temp_mk_path, '-f', temp_deps_path])
+		
+		deps = set(map(relpath, util.read_file(temp_files_path).decode().splitlines()))
+		ignored_files = set(map(relpath, [temp_deps_path, temp_mk_path, in_path, out_path]))
+		
+		_write_dependencies(deps_path, relpath(out_path), deps - ignored_files)
+
+
+main(*sys.argv[1:])