Figure Drawing

Academic Figure Drawing

CRITICAL RULES (read first)

1. NEVER inline TikZ code into paper sections. No \begin{tikzpicture} inside sections/*.tex or main.tex.
2. NEVER \input{figures/xxx.tex} a raw .tex file. The paper must use \includegraphics.
3. Every figure = standalone .tex → compile → PDF/PNG → \includegraphics.
4. Always compile and verify the standalone figure before inserting into the paper.

SOP

Step 1: Plan the figure

Before writing any code, decide:

• Type: taxonomy tree, architecture diagram, flowchart, bar/line chart, comparison table, timeline
• Content: what nodes/elements to show (read the relevant paper sections first)
• Layout direction: top-to-bottom or left-to-right (pick whichever avoids crowding)
• Estimated element count: if > 20 nodes, split into multiple figures

Step 2: Write the TikZ source

Write a standalone .tex file in figures/:

\documentclass[tikz,border=10pt]{standalone}
\usepackage[T1]{fontenc}
\usepackage{tikz}
\usetikzlibrary{positioning, arrows.meta, shapes, fit, backgrounds}
% Add other libraries as needed

\begin{document}
\begin{tikzpicture}[...]
  % figure content
\end{tikzpicture}
\end{document}

Step 3: Compile to PDF, then convert to PNG

cd figures/
pdflatex -interaction=nonstopmode xxx.tex
# Convert PDF to PNG (try available tools in order)
pdftoppm -png -r 300 xxx.pdf xxx_fig  # produces xxx_fig-1.png
# OR: convert xxx.pdf -density 300 xxx.png
# OR: sips -s format png xxx.pdf --out xxx.png  (macOS)

If pdftoppm / convert / sips are all unavailable, keep the PDF and use \includegraphics{figures/xxx.pdf} as fallback.

Step 4: Insert into paper

\begin{figure}[t]
  \centering
  \includegraphics[width=\columnwidth]{figures/xxx.png}
  \caption{Descriptive caption.}
  \label{fig:xxx}
\end{figure}

Step 5: Visual check

After compiling the full paper, verify the figure renders correctly and is referenced in the text with \ref{fig:xxx}.

Layout & Anti-overlap Rules (CRITICAL)

These rules prevent the most common failure — elements overlapping each other:

1. Use relative positioning, never absolute coordinates.

   \node[right=2cm of A] (B) {...};   % GOOD
   \node at (3,2) (B) {...};          % BAD — will overlap when content changes
   

2. Minimum spacing between nodes:

   • Siblings (same level): ≥ 1.2cm vertical, ≥ 2.0cm horizontal
   • Parent-child: ≥ 1.8cm
   • If text is long, increase spacing proportionally

3. Set minimum node size to fit content:

   minimum width=3cm, minimum height=0.9cm, text width=2.6cm, align=center
   

   Use text width to force line-wrapping for long labels.

4. For tree/taxonomy diagrams with many leaves:

   • Use grow=right or grow=down with level distance=2.5cm, sibling distance=1.5cm
   • If > 5 siblings at one level, increase sibling distance or stack in two columns

5. Test for overlap: after compilation, check the PDF visually. If any elements overlap, increase spacing and recompile before finalizing.

Style Guidelines

Colors — use muted, professional tones:

• Branch A: fill=blue!10, draw=blue!40
• Branch B: fill=teal!10, draw=teal!40
• Branch C: fill=orange!10, draw=orange!40
• Branch D: fill=violet!10, draw=violet!40
• Backgrounds: fill=gray!3

Text — minimum \footnotesize for any label. Use \small for node text, \normalsize\bfseries for titles. Never use \tiny.

Lines — draw=gray!50, arrow tip -{Stealth[length=5pt]}, line width 0.5pt.

Overall — generous whitespace. A figure that breathes is better than one that packs everything in. When in doubt, make it wider/taller.