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  <front>
    <journal-meta>
      <journal-title-group>
        <journal-title>First Workshop on Computational Design and Computer-aided Creativity</journal-title>
      </journal-title-group>
    </journal-meta>
    <article-meta>
      <title-group>
        <article-title>Ruled by Utopia: Procedurally Generated Mega-structures</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Guilherme L. Almeida</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>João M. Cunha</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Sérgio M. Rebelo</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Tiago Martins</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>(NumberOfSections</institution>
          ,
          <addr-line>MinimumTowerHeight, MaximumTowerHeight, FillerHeightTolerance, SectionContractionLimit, SectionExpansionLimit, WindowMinScaling, WindowMaxS- caling)</addr-line>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>University of Coimbra, CISUC/LASI - Centre for Informatics and Systems of the University of Coimbra, Department of Informatics Engineering</institution>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>Starting Surface; • Main Seed</institution>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2025</year>
      </pub-date>
      <volume>23</volume>
      <fpage>0000</fpage>
      <lpage>0001</lpage>
      <abstract>
        <p>Many building generation approaches focus on functional requirements or life-size concerns, creating a gap for aesthetic-focused building generation systems. We present a system that generates utopian mega-structures using procedural content generation techniques. Our goal is that the output of the system can serve as inspiration and visual explorations, or be materialized into dioramas, puzzles, scenographic elements, or graphic design material. Buildings can be much more than merely functional spaces. Fictional genres such as sci-fi and cyberpunk have presented audiences with ever-growing, busy buildings of questionable functionality that strive for visual appeal and creativity, while also speculating about what the future of architecture might look like. The idea for this system stems from these utopian notions, forgoing functionality to promote creative believability. The building generation system presented in this pictorial employs several Procedural Content Generation (PCG) techniques common in Procedural Generation of Buildings (PGB) [1], such as Generative Grammars (GG) [2, 3] and Pseudo-Random Number Generation (PRNG) [4, 5], and generates complete, non-furnished building models.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;Procedural Generation</kwd>
        <kwd>Computational Design</kwd>
        <kwd>Utopian Architecture</kwd>
        <kwd>Rule-Based Systems</kwd>
        <kwd>Generative Design</kwd>
        <kwd>Parametric Design</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Context</title>
    </sec>
    <sec id="sec-2">
      <title>2. Approach</title>
      <p>
        To make the most out of PRNG and GG techniques, we felt it would be useful to define and analyze a
target set of outputs from which we could abstract similarities, hierarchies, and variations. The main
architectural inspiration for this project was the work of Ana Aragão [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ], particularly the Vertical
Reclamation of Individual Spaces series, which we used as a guideline for the system’s current implementation.
Those illustrations serve as a prime example of what we plan to accomplish with this system: very
vertical, monumental and busy structures that border on surrealism, while still maintaining a level of
believability. Other influences include the Japanese Metabolism style, the works of Shin Takamatsu, or
Nigel Phelps’ work on Batman (1989), due to their vertical, modular and hierarchical nature. To the best
of our knowledge, there are no building generation systems based on these architectural references in
the literature.
      </p>
      <p>Given our set of target outputs, we opted for a common structure for all buildings: a series of vertically
disposed sections, comprised of several towers, whose walls are populated with modules (see Figure 1).
The building generation is controlled by the following set of parameters:
• Number of Sections;
• Minimum and Maximum Tower Height;
• Filler Height Tolerance;
• Section Contraction and Expansion Limit;
• Window Minimum and Maximum Scaling;</p>
      <p>First, the section bases are partitioned by a simple generative grammar. All terminal sections are then
extruded upward by a random height factor between MinimumTowerHeight and MaximumTowerHeight
to form towers. Having separated towers allows the system to individually customize and populate
diferent towers or parts of a section with diferent properties, not unlike what we see in our intended
outputs.</p>
      <p>Given the height diferences between towers, simply placing the next foundation over the tallest
tower would not look believable; therefore, the towers are then re-extruded if they are within a certain
height threshold, defined by FillerHeightTolerance (see Figure 2). The bounding box of the topmost areas
is then scaled up or down by a factor between SectionContractionLimit and SectionExpansionLimit, and
becomes the starting surface for the next section. This process is repeated a number of times equal to
NumberOfSections.</p>
      <p>Once all sections are generated, the system populates the visible walls with any number of
userdefined modules. First, the system filters out any faces or parts of faces that are not visible from the
outside. The height and width of each resulting face defines the upper and lower limits for the number
of rows and columns of a grid, and a 3D Simplex noise space selects the specific module to be placed at
each grid point, resized proportionately to the wall’s dimensions. In the future, we hope to accomplish
the module application step using GG techniques, rather than a noise space. The source code repository
can be found at: https://github.com/GuilhermeAlmeidaG8/LDC-Reclaimers.</p>
    </sec>
    <sec id="sec-3">
      <title>3. Results</title>
      <p>Our findings demonstrate that the system can create a wide variety of buildings, both with diferent
parameter sets and within each set (see Figures 4, 5 and ??). To this efect, we will present two
representative outputs for a few diferent parameter sets, highlighting the most relevant ones. The
parameters will be written in the figure captions, following this format:</p>
      <p>
        The results, although preliminary, already demonstrate the system’s possible applications. The final
models can be 3D printed to make scenographic elements at a variety of scales or be used as decorative
pieces (see Figure 6). Compositions of multiple buildings with varying styles can be created based
on their arrangement, and the buildings’ components can be separated into physical assembly kits or
puzzles, similar to Santos et al. [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ].
      </p>
    </sec>
    <sec id="sec-4">
      <title>Acknowledgments</title>
      <p>This work is funded by national funds through FCT – Foundation for Science and Technology, I.P.,
within the scope of the research unit UID/00326 - Centre for Informatics and Systems of the University
of Coimbra.</p>
    </sec>
    <sec id="sec-5">
      <title>Declaration on Generative AI</title>
      <p>During the preparation of this work, the authors used ChatGPT to: Paraphrase and reword, improve
writing style. After using this tool/service, the authors reviewed and edited the content as needed and
take full responsibility for the publication’s content.
Figure 7: Vectorized render of a set of buildings generated by the system.</p>
    </sec>
  </body>
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