diff -r 63b6f80e09ef -r a01a3fd32073 stl.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/stl.py	Mon Apr 03 19:40:06 2017 +0200
@@ -0,0 +1,68 @@
+import data, os, config, subprocess
+
+OPENSCAD_MODULES = """
+module tank(x, r, h) {
+  color("SteelBlue") render() { //rotate([90,0,0]) {
+    translate([x, r, r]) {
+        sphere(r = r); // bottom
+        cylinder(h = h-2*r, r = r);
+    }
+    translate([x, r, h-r]) {
+        sphere(r = r); // top
+        cylinder(h = r*1.4, r = r*0.25);
+    }
+  }
+}
+
+module spacer(x, r, rcyl, h) {
+  color("DarkGrey") render() { //rotate([90,0,0]) {
+    translate([x, r, rcyl]) {
+        difference() {
+            cylinder(h = h-2*rcyl, r = r);
+            cylinder(h = h-2*rcyl, r = r*0.8);
+        }
+    }
+  }
+}
+$fn = 25; // high detail per default
+"""
+
+def run_openscad(output):
+    if os.path.isfile(output):
+        print "skipping existing file %s" % output
+        return
+    print "rendering %s" % output
+    subprocess.check_call([
+        'openscad',
+        '-o',
+        output,
+        config.TMP_SCAD
+        ])
+
+def precompile_all_stl():
+    base = os.path.abspath('stl')
+    hmin = 9999
+    rmax = 0
+    for cyl in data.CYLINDER.keys():
+        with open(config.TMP_SCAD, "w") as fn:
+            fn.write(OPENSCAD_MODULES)
+            fn.write("tank(0, %f, %f);" % (
+                data.CYLINDER[cyl][0] / 2 * config.SCALE3D,
+                data.CYLINDER[cyl][1] * config.SCALE3D))
+        run_openscad(os.path.join(base,
+            'cylinder_' + cyl + '.stl'))
+        if data.CYLINDER[cyl][1] < hmin:
+            hmin = data.CYLINDER[cyl][1]
+        if data.CYLINDER[cyl][0] > rmax:
+            rmax = data.CYLINDER[cyl][0]
+
+    for pipe in data.PIPES:
+        with open(config.TMP_SCAD, "w") as fn:
+            fn.write(OPENSCAD_MODULES)
+            fn.write("spacer(0, %f, %f, %f);" % (
+                pipe[1] / 2 * config.SCALE3D,
+                rmax / 2 * config.SCALE3D,
+                hmin * config.SCALE3D))
+        run_openscad(os.path.join(base,
+            'spacer_' + pipe[0] + '.stl'))
+