Continuous Visible Query for Three-Dimensional Objects in Spatial Databases

<table class="figure-group"><tr class="fig-image" id="a"><td><object data="https://static-preview.hindawi.com/articles/mpe/volume-2016/6340856/figures/6340856.fig.003a.svgz" name="6340856.fig.003a" type="image/svg+xml"></object></td></tr><tr class="fig-caption"><td><b>(a) </b>3D object <svg height="12.4698pt" id="M41" style="vertical-align:-3.18147pt" version="1.1" viewbox="-0.0498162 -9.28833 58.0761 12.4698" width="58.0761pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M699 369C699 549 575 666 407 666C186 666 23 488 23 278C23 101 145 -16 312 -16C535 -16 699 153 699 369ZM600 373C600 210 500 19 321 19C186 19 120 129 120 272C120 450 232 631 399 631C541 631 600 522 600 373Z" id="g113-80"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="722" vert-adv-y="722"></glyph.data></g><g transform="matrix(.013,0,0,-0.013,9.387,0)"><path d="M300 -147C201 -63 143 98 143 270S200 602 300 686L282 710C136 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183L487 92C476 38 428 19 360 19C207 19 123 132 123 287C123 472 243 631 441 631C557 631 617 583 617 469L647 472C650 545 655 604 658 632C625 643 554 666 467 666C201 666 23 502 23 278C23 90 156 -16 339 -16C410 -16 501 6 569 24C566 43 567 70 573 101L589 183C604 259 607 262 667 271L673 297Z" id="g113-72"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="684" vert-adv-y="684"></glyph.data></g><g transform="matrix(.013,0,0,-0.013,37.055,0)"><path d="M95 130C70 130 46 113 46 88C46 72 54 64 59 64C93 55 121 33 121 -3C121 -41 93 -68 44 -88L55 -117C117 -98 186 -56 186 22C186 91 131 130 95 130Z" id="g113-45"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="228" vert-adv-y="228"></glyph.data></g><g transform="matrix(.013,0,0,-0.013,42.198,0)"><path d="M475 507C475 612 440 712 326 712C139 712 23 420 23 215C23 96 58 -12 180 -12C369 -12 475 293 475 507ZM391 522C391 486 387 448 379 394H126C155 538 222 677 310 677C386 677 391 571 391 522ZM373 346C344 193 283 22 189 22C126 22 106 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class="fig-caption"><td><b>(b) </b>Projection of 3D object in horizontal plane</td></tr><tr class="fig-image" id="c"><td><object data="https://static-preview.hindawi.com/articles/mpe/volume-2016/6340856/figures/6340856.fig.003c.svgz" name="6340856.fig.003c" type="image/svg+xml"></object></td></tr><tr class="fig-caption"><td><b>(c) </b>Projection angle as <svg height="9.49473pt" id="M42" style="vertical-align:-0.2063999pt" version="1.1" viewbox="-0.0498162 -9.28833 6.59789 9.49473" width="6.59789pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M475 507C475 612 440 712 326 712C139 712 23 420 23 215C23 96 58 -12 180 -12C369 -12 475 293 475 507ZM391 522C391 486 387 448 379 394H126C155 538 222 677 310 677C386 677 391 571 391 522ZM373 346C344 193 283 22 189 22C126 22 106 114 106 196C106 243 111 293 118 346H373Z" id="g113-230"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="498" vert-adv-y="498"></glyph.data></g></svg></td></tr></table>

<div>Projection in horizontal plane and projection angel in vertical plane.</div>

Mathematical Problems in Engineering

fig3

Figure 3

Figure 3: Continuous Visible Query for Three-Dimensional Objects in Spatial Databases 