rewrite manyfold analysis to use assimp scene

Author: Floppy

app/jobs/analysis/geometric_analysis_job.rb

@@ -9,15 +9,15 @@ class Analysis::GeometricAnalysisJob < ApplicationJob
   def perform(file_id)
     # Get model
     file = ModelFile.find(file_id)
-    return unless self.class.loader(file)
+    return unless file.loadable?
     if SiteSettings.analyse_manifold
       status[:step] = "jobs.analysis.geometric_analysis.loading_mesh" # i18n-tasks-use t('jobs.analysis.geometric_analysis.loading_mesh')
       # Get mesh
-      mesh = self.class.load_mesh(file)
-      if mesh
+      scene = file.scene
+      if scene
         status[:step] = "jobs.analysis.geometric_analysis.manifold_check" # i18n-tasks-use t('jobs.analysis.geometric_analysis.manifold_check')
-        # Check for manifold mesh
-        manifold = manifold?(mesh)
+        # Check that all meshes are manifold
+        manifold = scene.meshes.map { manifold?(it) }.all?
         Problem.create_or_clear(
           file,
           :non_manifold,
@@ -40,46 +40,30 @@ def perform(file_id)
     end
   end
 
-  def self.loader(file)
-    case file.extension.downcase
-    when "stl"
-      Mittsu::STLLoader
-    when "obj"
-      Mittsu::OBJLoader
-    end
-  end
-
-  def self.load_mesh(file)
-    # TODO: This can be better, but needs changes upstream in Mittsu to allow loaders to parse from an IO object
-    loader(file)&.new&.parse(file.attachment.read)
-  end
-
   private
 
   def manifold?(mesh)
     # Shortcut if there is nothing here
-    return true if mesh.geometry.nil? && mesh.children.empty?
-    # Recurse children to see if they are manifold
-    children_are_manifold = mesh.children.map { |x| manifold?(x) }.all?
+    return true if mesh.num_faces == 0
     # Detect manifold geometry in this object
     edges = {}
     # For each face, record its edges in the edge hash
-    mesh.geometry&.faces&.each do |face|
-      update_edge_hash face.a, face.b, edges
-      update_edge_hash face.b, face.c, edges
-      update_edge_hash face.c, face.a, edges
+    mesh.faces.each do |face|
+      update_edge_hash face.indices[0], face.indices[1], edges
+      update_edge_hash face.indices[1], face.indices[2], edges
+      update_edge_hash face.indices[2], face.indices[0], edges
     end
     # If there's anything left in the edge hash, then either
     # we have holes, or we have badly oriented faces
-    edges.empty? && children_are_manifold
+    edges.empty?
   end
 
   # Updates edge hash with the passed vertex indexes
   # First, the reverse edge is searched for in the hash
   # If found, it's removed as we've got a match
   # If not, we record this edge in the hash
   def update_edge_hash(v1, v2, edges)
-    return if edges.delete "#{v2}->#{v1}"
-    edges["#{v1}->#{v2}"] = true
+    return if edges.delete [v2, v1].pack("QQ")
+    edges[[v1, v2].pack("QQ")] = true
   end
 end