Initial MoonModel implementation

lib/moon_model/three_mf.rb

@@ -0,0 +1,126 @@
+# frozen_string_literal: true
+
+require "cgi"
+require "zip"
+
+module MoonModel
+  class ThreeMF
+    CONTENT_TYPES = <<~XML.freeze
+      <?xml version="1.0" encoding="UTF-8"?>
+      <Types xmlns="http://schemas.openxmlformats.org/package/2006/content-types">
+        <Default Extension="rels" ContentType="application/vnd.openxmlformats-package.relationships+xml"/>
+        <Default Extension="model" ContentType="application/vnd.ms-package.3dmanufacturing-3dmodel+xml"/>
+      </Types>
+    XML
+    RELATIONSHIPS = <<~XML.freeze
+      <?xml version="1.0" encoding="UTF-8"?>
+      <Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">
+        <Relationship Target="/3D/3dmodel.model" Id="rel0" Type="http://schemas.microsoft.com/3dmanufacturing/2013/01/3dmodel"/>
+      </Relationships>
+    XML
+
+    def self.write(path, meshes, metadata: {}, palette: [])
+      raise ArgumentError, "3MF needs at least one mesh" if meshes.empty?
+      meshes.each { |mesh| raise ArgumentError, "invalid mesh #{mesh.name}" unless mesh.valid? }
+
+      materials = ordered_materials(meshes, palette)
+      model = build_model(meshes, metadata, materials)
+      model_settings = build_bambu_model_settings(meshes, metadata, materials)
+      FileUtils.mkdir_p(File.dirname(path))
+      Zip::File.open(path, create: true) do |zip|
+        zip.get_output_stream("[Content_Types].xml") { |io| io.write(CONTENT_TYPES) }
+        zip.get_output_stream("_rels/.rels") { |io| io.write(RELATIONSHIPS) }
+        zip.get_output_stream("3D/3dmodel.model") { |io| io.write(model) }
+        zip.get_output_stream("Metadata/model_settings.config") { |io| io.write(model_settings) }
+      end
+      path
+    end
+
+    def self.build_model(meshes, metadata, materials = ordered_materials(meshes, []))
+      material_index = materials.each_with_index.to_h { |item, index| [[item["name"], item["hex"]], index] }
+      labels = mesh_labels(meshes, materials)
+      xml = +%(<?xml version="1.0" encoding="UTF-8"?>\n)
+      xml << %(<model unit="millimeter" xml:lang="en-US" xmlns="http://schemas.microsoft.com/3dmanufacturing/core/2015/02">\n)
+      metadata.each { |key, value| xml << %(<metadata name="#{escape(key)}">#{escape(value)}</metadata>\n) }
+      xml << "<resources>\n"
+      unless materials.empty?
+        xml << %(<basematerials id="1">\n)
+        materials.each { |item| xml << %(<base name="#{escape(item["name"])}" displaycolor="#{escape(item["hex"].upcase)}"/>\n) }
+        xml << "</basematerials>\n"
+      end
+      meshes.each_with_index do |mesh, index|
+        id = index + 2
+        attrs = mesh.material ? %( pid="1" pindex="#{material_index.fetch([mesh.material["name"], mesh.material["hex"]])}") : ""
+        xml << %(<object id="#{id}" name="#{escape(labels[index])}" type="model"#{attrs}><mesh><vertices>\n)
+        mesh.vertices.each { |x, y, z| xml << %(<vertex x="#{fmt(x)}" y="#{fmt(y)}" z="#{fmt(z)}"/>\n) }
+        xml << "</vertices><triangles>\n"
+        mesh.triangles.each { |a, b, c| xml << %(<triangle v1="#{a}" v2="#{b}" v3="#{c}"/>\n) }
+        xml << "</triangles></mesh></object>\n"
+      end
+      assembly_id = meshes.length + 2
+      if meshes.length > 1
+        xml << %(<object id="#{assembly_id}" name="#{escape(wrapper_name(metadata))}" type="model"><components>\n)
+        meshes.each_index { |index| xml << %(<component objectid="#{index + 2}"/>\n) }
+        xml << "</components></object>\n"
+      end
+      xml << "</resources><build>\n"
+      xml << %(<item objectid="#{meshes.length > 1 ? assembly_id : 2}"/>\n)
+      xml << "</build></model>\n"
+      xml
+    end
+
+    def self.ordered_materials(meshes, palette)
+      used = meshes.filter_map(&:material).uniq { |item| [item["name"], item["hex"]] }
+      (palette + used).uniq { |item| [item["name"], item["hex"].upcase] }
+    end
+
+    def self.mesh_labels(meshes, materials)
+      meshes.map do |mesh|
+        unless mesh.material
+          next "#{humanize(mesh.name)} — material unassigned"
+        end
+        slot = materials.index { |item| item["name"] == mesh.material["name"] && item["hex"].casecmp?(mesh.material["hex"]) } + 1
+        role = if mesh.name.end_with?("_structure")
+          "Structure"
+        elsif mesh.name == "assembly_keys"
+          "Assembly keys"
+        else
+          "Surface"
+        end
+        "#{role} — #{mesh.material["name"]} (#{mesh.material["hex"].upcase}) — Filament #{slot}"
+      end
+    end
+
+    def self.build_bambu_model_settings(meshes, metadata, materials)
+      labels = mesh_labels(meshes, materials)
+      object_id = meshes.length > 1 ? meshes.length + 2 : 2
+      xml = +%(<?xml version="1.0" encoding="UTF-8"?>\n<config>\n)
+      xml << %(  <object id="#{object_id}">\n)
+      xml << %(    <metadata key="name" value="#{escape(wrapper_name(metadata))}"/>\n)
+      meshes.each_with_index do |mesh, index|
+        xml << %(    <part id="#{index + 2}" subtype="normal_part">\n)
+        xml << %(      <metadata key="name" value="#{escape(labels[index])}"/>\n)
+        if mesh.material
+          slot = materials.index { |item| item["name"] == mesh.material["name"] && item["hex"].casecmp?(mesh.material["hex"]) } + 1
+          xml << %(      <metadata key="extruder" value="#{slot}"/>\n)
+        end
+        xml << "    </part>\n"
+      end
+      xml << "  </object>\n  <assemble/>\n</config>\n"
+      xml
+    end
+
+    def self.wrapper_name(metadata)
+      title = metadata.fetch("Title", "Moon")
+      part = metadata["Part"]
+      part && !part.empty? ? "#{title} — #{part}" : title
+    end
+
+    def self.humanize(value) = value.to_s.tr("_", " ").split.map(&:capitalize).join(" ")
+
+    def self.escape(value) = CGI.escapeHTML(value.to_s)
+    def self.fmt(value) = format("%.6f", value).sub(/\.?0+\z/, "")
+    private_class_method :escape, :fmt, :ordered_materials, :mesh_labels, :build_bambu_model_settings,
+                         :wrapper_name, :humanize
+  end
+end