Class: ObjParser::Obj

Inherits:
Object
  • Object
show all
Defined in:
lib/obj_parser/obj.rb

Constant Summary collapse

VERTEX_BY_FACE = 
3

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Obj

Returns a new instance of Obj.



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# File 'lib/obj_parser/obj.rb', line 13

def initialize
  self.vertice = []
  self.normals = []
  self.textures = []
  self.tangents = []
  self.vertice_indexes = []
  self.normals_indexes = []
  self.textures_indexes = []
  self.tangents_indexes = []
end

Instance Attribute Details

#faces ⇒ Object

Returns the value of attribute faces.



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# File 'lib/obj_parser/obj.rb', line 11

def faces
  @faces
end

#normals ⇒ Object

Returns the value of attribute normals.



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# File 'lib/obj_parser/obj.rb', line 7

def normals
  @normals
end

#normals_indexes ⇒ Object

Returns the value of attribute normals_indexes.



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# File 'lib/obj_parser/obj.rb', line 7

def normals_indexes
  @normals_indexes
end

#tangents ⇒ Object

Returns the value of attribute tangents.



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# File 'lib/obj_parser/obj.rb', line 10

def tangents
  @tangents
end

#tangents_indexes ⇒ Object

Returns the value of attribute tangents_indexes.



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# File 'lib/obj_parser/obj.rb', line 10

def tangents_indexes
  @tangents_indexes
end

#textures ⇒ Object

Returns the value of attribute textures.



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# File 'lib/obj_parser/obj.rb', line 9

def textures
  @textures
end

#textures_indexes ⇒ Object

Returns the value of attribute textures_indexes.



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# File 'lib/obj_parser/obj.rb', line 9

def textures_indexes
  @textures_indexes
end

#vertice ⇒ Object

Returns the value of attribute vertice.



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# File 'lib/obj_parser/obj.rb', line 8

def vertice
  @vertice
end

#vertice_indexes ⇒ Object

Returns the value of attribute vertice_indexes.



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# File 'lib/obj_parser/obj.rb', line 8

def vertice_indexes
  @vertice_indexes
end

Instance Method Details

#compute_tangents ⇒ Object 



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# File 'lib/obj_parser/obj.rb', line 37

def compute_tangents
	self.tangents = []
	self.tangents_indexes = []
  return if textures.count == 0 || normals.count == 0
  self.resolve_faces
	pindex = 0
	self.faces.each do |face|
  	pindex += 1
		tangent_for_face = MathUtils::tangent_for_vertices_and_texures(face.vertice.map(&:data), face.textures.map(&:data))
		tangent_for_face = MathUtils::normalized_vector(tangent_for_face)
		#set the same tangent for the 3 vertex of current face
		#re-compute tangents for duplicates vertices to get tangent per face
		face.vertice.each_with_index do |vertex, index|
			vertex.tangent.data = MathUtils::sum_vectors(vertex.tangent.data, tangent_for_face)
		end
  end
	
	#orthonormalize
	self.faces.each_with_index do |face,pindex|
	  face.vertice.each_with_index do |vertex, index|
		vertex.tangent.data = MathUtils::orthogonalized_vector_with_vector(vertex.tangent.data, self.normals[self.normals_indexes[pindex * 3 + index]].data)
		vertex.tangent.data = MathUtils::normalized_vector(vertex.tangent.data)
   	 end
	end
	
	#binormal should be computed with per vertex tangent and summed for each vertex
	self.faces.each_with_index do |face,pindex|
		face.vertice.each_with_index do |vertex, index|
			binormal = MathUtils::cross_product(self.normals[self.normals_indexes[pindex * 3 + index]].data, vertex.tangent.data)
			vertex.binormal.data = MathUtils::sum_vectors(vertex.binormal.data, binormal)
		end
	end
	
	self.faces.each_with_index do |face,pindex|
	  face.vertice.each_with_index do |vertex, index|
  		vertex.binormal.data = MathUtils::normalized_vector(vertex.binormal.data)
  		if(MathUtils::dot(MathUtils::cross_product(self.normals[self.normals_indexes[pindex * 3 + index]].data, vertex.tangent.data), vertex.binormal.data) < 0.0)
  			vertex.tangent.data[3] = -1.0 
  		else
  			vertex.tangent.data[3] = 1.0 
  		end
    end
  end

	self.faces.each_with_index do |face, index|
		self.tangents += face.vertice.map(&:tangent)
		point_index = index * 3
		self.tangents_indexes += [point_index, point_index + 1, point_index + 2]
	end
end

#resolve_faces ⇒ Object 



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# File 'lib/obj_parser/obj.rb', line 24

def resolve_faces
  self.faces = (self.vertice_indexes.count / VERTEX_BY_FACE).times.map { Face.new }
  self.faces.each_with_index do |face, face_index|
    [:vertice, :normals, :textures, :tangents].each do |element|
      point_indexes = (self.send("#{element}_indexes")[face_index * VERTEX_BY_FACE..-1] || []).take(VERTEX_BY_FACE)
      points = point_indexes.map do |point_index|
        self.send(element)[point_index]
      end
      face.send("#{element}=", points)
    end
  end
end

#tangents_self_check ⇒ Object 



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# File 'lib/obj_parser/obj.rb', line 88

def tangents_self_check
  self.resolve_faces
  result = self.faces.each_with_index.map do |face, index| 
		face.vertice.map do |vertex|
		  ("%.2f" % MathUtils::dot(vertex.tangent.data[0..2], vertex.normal.data)).to_f
		end.reduce(&:+)
  end.reduce(&:+)
  puts "RESULT: tangents and normals are orthogonal -> [#{result == 0 ? "VALID" : "NOT VALID"}]"
  result == 0
end