tweak the fit of the parts

cases/gps/build.rb

@@ -44,13 +44,18 @@ config = YAML.safe_load_file(ROOT.join("case.yml"), permitted_classes: [],
                              permitted_symbols: [], aliases: false)
 openscad = executable("OPENSCAD", "openscad")
 blender = executable("BLENDER", "blender")
+python = executable("PYTHON", "python3")
 abort "OpenSCAD not found; install it or set OPENSCAD" unless openscad
 abort "Blender not found; install it or set BLENDER" unless blender
 
 parameters = config.fetch("parameters").merge(
   "extra_cutouts" => config.fetch("resolved").fetch("extra_cutouts")
 )
+artwork = !parameters.fetch("lid_label", "").empty? ||
+          parameters.fetch("lid_logo_enabled", false)
+abort "Python 3 not found; install it or set PYTHON" if artwork && !python
 parts = %w[body lid] + config.fetch("outputs").fetch("coupons")
+parts.concat(%w[lid_base lid_accent]) if artwork
 buttons = %w[button_a button_b button_c button_reset]
 if parameters["top_profile"] == "oled128x64" &&
    buttons.any? { |name| parameters[name] }
@@ -80,6 +85,16 @@ begin
       puts "Exporting #{part}.#{format}…"
       export.call(directory.join("#{part}.#{format}"), part)
     end
+    if artwork && format == "3mf"
+      puts "Packaging lid_multicolor.3mf…"
+      run!(
+        python, ROOT.join("tools/package_multimaterial_3mf.py").to_s,
+        directory.join("lid_base.3mf").to_s,
+        directory.join("lid_accent.3mf").to_s,
+        directory.join("lid_multicolor.3mf").to_s,
+        "--title", "#{config.fetch("name")} Lid"
+      )
+    end
   end
 
   assembly = scratch.join("assembly.stl")
@@ -97,6 +112,16 @@ begin
     run!(blender, "--background", "-noaudio", "--python", renderer.to_s, "--",
          mesh.to_s, previews.to_s, part, "iso", env: render_env)
   end
+  if artwork
+    puts "Rendering multicolor lid preview…"
+    run!(
+      blender, "--background", "-noaudio", "--python",
+      ROOT.join("source/render_multicolor_lid.py").to_s, "--",
+      scratch.join("lid_base.stl").to_s,
+      scratch.join("lid_accent.stl").to_s,
+      previews.to_s, "lid_multicolor", parameters["lid_art_orientation"], env: render_env
+    )
+  end
 
   backup = ROOT.join(".build-old-#{Process.pid}")
   FileUtils.mkdir_p(backup)