Exploring modelX in ruby processing

############################
# processing modelX
# examples in ruby processing
###########################


def setup
  size 500, 500, P3D
  no_fill
end

def draw
  background 0
 
  push_matrix
  # start at the middle of the screen
  translate(width/2, height/2, -200)    
  # some pseudo random rotation to make things interesting
  rotate_y 1.0 # yrot
  rotate_z 2.0 # zrot
  # rotate in X a little more each frame
  rotate_x(frame_count / 100.0)
  # offset from center
  translate(0, 150, 0)
 
  # draw a white box outline at (0, 0, 0)
  stroke 255
  box 80
 
  # the box was drawn at (0, 0, 0), store that location
  x = model_x(0, 0, 0)
  y = model_y(0, 0, 0)
  z = model_z(0, 0, 0)
  # clear out all the transformations
  pop_matrix

  # draw another box at the same (x, y, z) coordinate as the other
  push_matrix
  translate(x, y, z)
  stroke(255, 0, 0)
  box 80
  pop_matrix
end

Exploring screenX in ruby processing

I think there is a mistake in the version at the processing wiki (which I have flagged) because the 2D lines mentioned in the comments have six parameters (in my book that is 3D line even if Z is zero). You still get to see the parallax in my amended version, try it.


###################
# processing screenX example
# in ruby processing
###################

def setup
  size 100, 100, P3D
end

def draw
  background 204
  
  x = mouse_x
  y = mouse_y
  z = -100
  
  # Draw "X" at z = -100
  stroke 255
  line(x - 10, y - 10, z, x + 10, y + 10, z)
  line(x + 10, y - 10, z, x - 10, y + 10, z)
  
  # Draw line in 2D at same x value
  # Notice the parallax
  stroke 102
  line(x, 0, x, height)
  
  # Draw 2D line to match the x value
  # element drawn at z = -100
  stroke(0)
  the_x = screen_x(x, y, z)
  line(the_x, 0, the_x, height)    
end

Winged Edge Mesh and Physics from Toxiclibs

Here is the toxiclibs InflateMesh verlet physics example demonstrating winged mesh class functionality. Although this was a P3D sketch in the example it looks best using OPENGL. Because there is still an issue with linux and ruby-processing OPENGL at less than full_screen, I have scaled some of the variables in the sketch (mainly annotated I think), anyway you should probably look at the original (included in the library download toxiclibs-complete version 0020).



# <p>This example uses the attraction behavior to inflate a 3D mesh.
# The mesh vertices are re-created as physics particles and connected
# using springs. Upon mouse press the inflation force is applied,
# counteracting the forces created by the springs, causing the mesh to
# expand and deform.</p>
#
# <p>Usage: Click and hold mouse button to inflate mesh</p>
#

############
# Copyright (c) 2010 Karsten Schmidt translated to ruby processing by Martin Prout (Spring 2011)
#
# This demo & library is free software you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation either
# version 2.1 of the License, or (at your option) any later version.
#
# http:#creativecommons.org/licenses/LGPL/2.1/
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
#
class InflateMesh < Processing::App
  load_libraries 'toxiclibs_p5', 'toxiclibscore', 'verletphysics', 'opengl'
  include_package 'processing.opengl'
  include_package 'toxi.geom'
  include_package 'toxi.geom.mesh.subdiv'
  include_package 'toxi.geom.mesh'
  include_package 'toxi.physics'
  include_package 'toxi.physics.behaviors'
  include_package 'toxi.physics.constraints'
  include_package 'toxi.processing'

  attr_reader :physics, :inflate, :box, :gfx
  full_screen

  def setup
    setup_opengl
    @gfx = ToxiclibsSupport.new(self)
    init_physics
  end

  def draw
    @physics.update()
    for vert in box.vertices.values
      vert.set(physics.particles.get(vert.id))
    end
    box.center(nil)              # nil means centre at 0, 0, 0
    for vert in box.vertices.values
      @physics.particles.get(vert.id).set(vert)
    end
    box.compute_face_normals
    box.face_outwards
    box.compute_vertex_normals
    background(51)
    translate(width / 2, height / 2, 0)
    rotate_x((height / 2 - mouse_y) * 0.01)
    rotate_y((width / 2 - mouse_x) * 0.01)
    no_fill
    lights
    directional_light(255, 255, 255, -200, 1000, 500)
    specular(255)
    shininess(16)
    @gfx.origin(Vec3D.new, 300)  # scaled up axes display from 50
    fill(192)
    no_stroke
    @gfx.mesh(box, true, 10)     # scaled up normals display from 5
  end

  def init_physics
    @box = WETriangleMesh.new
    # create a simple start mesh
    #box.add_mesh(Cone.new(Vec3D.new(0, 0, 0), Vec3D.new(0, 1, 0), 10, 50, 100).to_mesh(4))
    @box.add_mesh(AABB.new(Vec3D.new, 150).to_mesh)      # scaled up from 50
    # then subdivide a few times...
    @box.subdivide
    @box.subdivide
    @box.subdivide
    @box.subdivide
    @physics = VerletPhysics.new
    @physics.set_world_bounds(AABB.new(Vec3D.new, 540))  # scaled up from 180
    # turn mesh vertices into physics particles
    for vert in box.vertices.values
      @physics.add_particle(VerletParticle.new(vert))
    end
    # turn mesh edges into springs
    for w_edge in box.edges.values
      vp_a = physics.particles.get(w_edge.a.id)
      vp_b = physics.particles.get(w_edge.b.id)
      @physics.add_spring(VerletSpring.new(vp_a, vp_b, vp_a.distance_to(vp_b), 0.05))
    end
  end

  def key_pressed     # using a switch anticipating more key actions
    case key
    when 'i'
    init_physics
    when 's'
    save_frame "inflate.png"
    end
  end


  def mouse_pressed
    @inflate=AttractionBehavior.new(Vec3D.new, 400, -0.3, 0.001)
    @physics.add_behavior(inflate)
  end

  def mouse_released
    @physics.remove_behavior(inflate)
  end

  def setup_opengl
    render_mode OPENGL
    hint ENABLE_OPENGL_4X_SMOOTH     # optional
    hint DISABLE_OPENGL_ERROR_REPORT # optional
  end
end

Using Hemesh Library in ruby-processing

It has been positively ages since I last posted any ruby-processing sketches here is one processing library that you might like to experiment with it is the Hemesh library by Frederik Vanhoutte aka W:Blut. Over on my other blog I have been describing the development of my latest processing library "povwriter" a tool for exporting processing sketches to the povray format and this is one of the sketches I have used.  Next I will attempt to get my "povwriter" library working in ruby processing.


# RandomCage.rb is a processing sketch that shows
# how you can use the Hemesh library in Ruby-Processing.


class RandomCage < Processing::App
  load_libraries 'hemesh', 'opengl'
  include_package 'wblut.hemesh'
  include_package 'wblut.hemesh.creators'
  include_package 'wblut.hemesh.iterators'
  include_package 'wblut.hemesh.modifiers'
  include_package 'wblut.hemesh.subdividors'

  import "processing.opengl"

  full_screen
  TWO_PI = Math::PI * 2
  attr_reader :cage

  def setup
    configure_opengl
    @cage = HE_Mesh.new(HEC_Box.new(self).set_depth(height/2).set_height(height/2).set_width(height/2))
    @cage.modify(HEM_ChamferCorners.new.set_distance(height*0.1))
    #HES_Planar() subdivision can include a measure of randomness
    @cage.subdivide(HES_Planar.new.set_random(true).set_range(0.4),2)
 
    #A save choice after introducing any kind of randomness is to triangulate possible concave faces.
    #Concave faces do not invalidate the mesh but can give unexpected results.
    @cage.triangulate_concave_faces()
 
    @cage.modify(HEM_Lattice.new.set_depth(0.016*height).set_width(0.016*height).set_fuse(true))
    sel = HE_Selection.new
    for f in cage.f_itr        # using ruby syntax here
      sel.add f
    end
    cage.subdivide_selected(HES_CatmullClark.new(),sel,2)
  end


  def draw
    background(120)
    lights
    translate(width/2, height/2)
    rotate_y(mouse_x * 1.0  / width * TWO_PI - Math::PI)
    rotate_x(mouse_y * 1.0 / height * TWO_PI - Math::PI)
    fill(255)
    no_stroke
    cage.draw_faces
    stroke(0)  
    cage.draw_edges
  end

  def configure_opengl
    render_mode OPENGL
    hint ENABLE_OPENGL_4X_SMOOTH     # optional
    hint DISABLE_OPENGL_ERROR_REPORT # optional
  end

end