# Module: Kamelopard::Multicam

Defined in:
lib/kamelopard/multicam.rb

## Class Method Details

### .cross_product(v1, v2) ⇒ Object

 ``` 6 7 8 9 10 11``` ```# File 'lib/kamelopard/multicam.rb', line 6 def self.cross_product(v1, v2) x = ( (v1[1] * v2[2]) - (v1[2] * v2[1]) ) y = - ( (v1[0] * v2[2]) - (v1[2] * v2[0]) ) z = ( (v1[0] * v2[1]) - (v1[1] * v2[0]) ) return Vector[x, y, z] end```

### .dotprod_angle(a, b, negate = false) ⇒ Object

 ``` 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29``` ```# File 'lib/kamelopard/multicam.rb', line 13 def self.dotprod_angle(a, b, negate = false) begin d = 180.0 * (Math.acos(a.inner_product(b) / a.r / b.r)) / Math::PI rescue d = 0 #puts "argument was #{a.inner_product(b)}, from vectors #{a} and #{b}" end d = 0 if d.respond_to? :nan? and d.nan? raise "#{a}, #{b}, #{a.inner_product(b)}" if d == Float::INFINITY # Complicating factor: dot product goes from 0 to 180, not 0 to 360. We'll # have to know whether to negate based on external input (like if the # original angle involved was close to the threshold) d = -d if negate return d end```

### .get_camera(heading, tilt, roll, cam_num, cam_angle, cam_count = nil) ⇒ Object

 ``` 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121``` ```# File 'lib/kamelopard/multicam.rb', line 105 def self.get_camera(heading, tilt, roll, cam_num, cam_angle, cam_count = nil) if cam_angle.nil? then cam_angle = cam_num * 360.0 / cam_count else cam_angle = cam_angle * cam_num end # The camera vector is [0,0,1] rotated around the Y axis the amount # of the camera angle camera = rot_y(cam_angle) * Vector[0,0,1] # The up vector is the same for all cameras up = Vector[0,1,0] matrix = rot_z(heading) * rot_x(tilt) * rot_z(roll) (h, t, r) = vector_to_camera(matrix * camera, matrix * up) # XXX What am I getting wrong, to require the negated roll? return [h, t, -1 * r] end```

### .get_camera_view(v, cam_num, cam_angle, cam_count = nil) ⇒ Object

 ``` 123 124 125 126 127 128 129``` ```# File 'lib/kamelopard/multicam.rb', line 123 def self.get_camera_view(v, cam_num, cam_angle, cam_count = nil) (h, t, r) = get_camera(v.heading, v.tilt, v.roll, cam_num, cam_angle, cam_count) v.heading = h v.tilt = t v.roll = r v end```

### .make_placemark(name, lat, lon, alt, tilt, roll, heading) ⇒ Object

 ``` 97 98 99 100 101 102 103``` ```# File 'lib/kamelopard/multicam.rb', line 97 def self.make_placemark(name, lat, lon, alt, tilt, roll, heading) p = point(lon, lat, alt, :relativeToGround) l = camera p, :heading => heading, :tilt => tilt, :roll => roll, :altitudeMode => :relativeToGround pl = placemark(name, :geometry => p, :abstractView => l) f = get_folder f << pl end```

### .rot_x(a) ⇒ Object

 ``` 31 32 33 34 35 36``` ```# File 'lib/kamelopard/multicam.rb', line 31 def self.rot_x(a) # This, and the other two rotation matrix functions, must convert # the angle to radians a = a * Math::PI / 180.0 return Matrix[[1, 0, 0], [0, Math.cos(a), -1 * Math.sin(a)], [0, Math.sin(a), Math.cos(a)]] end```

### .rot_y(a) ⇒ Object

 ``` 38 39 40 41``` ```# File 'lib/kamelopard/multicam.rb', line 38 def self.rot_y(a) a = a * Math::PI / 180.0 return Matrix[[Math.cos(a), 0, Math.sin(a)], [0, 1, 0], [-1 * Math.sin(a), 0, Math.cos(a)]] end```

### .rot_z(a) ⇒ Object

 ``` 43 44 45 46``` ```# File 'lib/kamelopard/multicam.rb', line 43 def self.rot_z(a) a = a * Math::PI / 180.0 return Matrix[[Math.cos(a), -1 * Math.sin(a), 0], [Math.sin(a), Math.cos(a), 0], [0, 0, 1]] end```

 ``` 48 49 50 51 52 53``` ```# File 'lib/kamelopard/multicam.rb', line 48 def self.same_quadrant(a, b) (0..2).each do |i| return false if (a[i] > 0 and b[i] < 0) or (a[i] < 0 and b[i] > 0) end return true end```
 ``` 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186``` ```# File 'lib/kamelopard/multicam.rb', line 131 def self.test(kml_name = 'multicam_test.kml') name_document 'tourvid' get_document().open = 1 [:roll, :tilt, :heading].each do |which| camera = Vector[0,0,1] heading = 0 tilt = 45 roll = 0 lat = 40 lon = -111 alt = 100 puts "------------------" puts "Running #{which}" folder which.to_s get_folder().open = 1 up = Vector[0,1,0] (0..36).each do |i| if which == :roll then roll = -180 + i * 10 heading = 23 elsif which == :heading then heading = i * 10 heading = heading - 360 if heading >= 180 else tilt = i * 5 end # This has been verified visually as the right matrix matrix = rot_z(heading) * rot_x(tilt) * rot_z(roll) trans_up = matrix * up trans_cam = matrix * camera trans_cross = cross_product(trans_cam, trans_up) (screen_head, screen_tilt, screen_roll) = vector_to_camera(trans_cam, trans_up) diff_limit = 3 a = dotprod_angle(trans_up, trans_cam) if ((heading - screen_head).abs > diff_limit or (tilt - screen_tilt).abs > diff_limit or (roll - screen_roll).abs > diff_limit) then #if which == :roll then puts " PLACEMARK #{i}" # puts " Camera vector: #{trans_cam}, mag: #{trans_cam.r}" # puts " Up vector: #{trans_up}, mag: #{trans_up.r}" # puts " Cross prod: #{trans_cross}, mag: #{trans_cross.r}" puts " UpZ: #{trans_up[2]}" puts " Orig H/T/R: #{heading}/#{tilt}/#{roll}" puts " Screen H/T/R: #{screen_head}/#{screen_tilt}/#{screen_roll}" end make_placemark(i, lat, lon, alt, screen_tilt, screen_roll, screen_head) end puts write_kml_to kml_name end end```
 ``` 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95``` ```# File 'lib/kamelopard/multicam.rb', line 56 def self.vector_to_camera(vec, up_vec) # The heading is the angle between two planes, the first formed by the # camera vector and the original Z axis, and the second formed by the # original Y and Z axes. This angle between two planes is the same # as the angle between their two normals. The normal of the first # plane is the cross product of the two vector, and that of the # second is simply the X axis. The first cross product will be zero # if the camera position vector is parallel to the Z axis; in that # case we want the angle between the up vector and the y axis # This will only find values up to 180 degrees, and won't # distinguish direction correctly. For that, look at the Z # component of the cross product of the two normals. cam_z_norm = cross_product(vec, Vector[0,0,-1]) if cam_z_norm.r == 0 heading = dotprod_angle(up_vec, Vector[0,1,0], (cross_product(up_vec, Vector[0,1,0])[2] > 0)) else heading = dotprod_angle(cam_z_norm, Vector[1,0,0], (cross_product(cam_z_norm, Vector[1,0,0])[2] > 0)) end # Tilt is calculated from the vector alone, and is the angle between it and # the original Z axis, calculated via the dot product tilt = dotprod_angle(vec, Vector[0,0,1]) # For roll, take the original UP vector, and now that I've got # valid heading and tilt, transform it by those values. Take the # angle between it and my current UP vector. Make it negative if # their cross product, up vector first, isn't the same direction as # the camera vector. transformed_up = rot_z(heading) * rot_x(tilt) * Vector[0,1,0] if cross_product(up_vec, transformed_up).r == 0 negate = ! (same_quadrant(up_vec, transformed_up)) else negate = same_quadrant(vec, cross_product(up_vec, transformed_up)) end roll = dotprod_angle(up_vec, transformed_up, negate) return [heading, tilt, roll] end```