Stories with Tag graphics

• Slugs on a Cube: An Interactive Animation

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  Posted: 2025-01-16 22:13:56

  Verbose tl;dr

  Gingerbeardman's blog post presents an interactive animation exploring the paths of two slugs crawling on the surface of a cube. The slugs start at opposite corners and move at the same constant speed, aiming directly at each other. The animation allows viewers to adjust parameters like slug speed and starting positions to see how these changes affect the slugs' paths, which often involve spiraling towards a meeting point but never actually colliding. The post showcases the intriguing mathematical problem of pursuit curves in a visually engaging way.

  This blog post, titled "Slugs on a Cube: An Interactive Animation," by Simon Jackson, presents a captivating visualization exploring the intriguing mathematical problem of slugs traversing the faces of a cube. The author meticulously details the creation of an interactive animation that allows users to dynamically manipulate the initial positions of two slugs on a cube and observe their hypothetical paths as they attempt to reach each other.

  Jackson begins by outlining the core problem: two slugs are placed on different faces of a cube, and they desire to meet as quickly as possible. The slugs can move freely across any face but cannot jump or fly; they are constrained to the surface of the cube. The challenge is to determine the optimal path each slug should take to minimize the travel time to their rendezvous point.

  The post then delves into the complexities of solving this problem, noting that simply traveling in a straight line across a face towards the other slug's perceived location isn't necessarily the fastest route. Due to the three-dimensional nature of the cube, the shortest path may involve traversing multiple faces. Unfolding the cube's net, a two-dimensional representation of its surface, is introduced as a crucial tool for visualizing and calculating these optimal paths. Jackson explains how the paths appear as straight lines on the unfolded net, despite appearing more complex on the three-dimensional cube itself.

  The author proceeds to describe the technical implementation of the interactive animation, highlighting the use of JavaScript and HTML5 canvas elements. He details the process of mapping three-dimensional coordinates on the cube to two-dimensional coordinates on the unfolded net, a critical step in accurately rendering the slugs' movements. Furthermore, the post elaborates on the algorithms employed to calculate the shortest paths, taking into account the various possible unfoldings of the cube net. The interactive element allows users to drag and drop the slugs to different starting positions, dynamically recalculating and redrawing the optimal paths in real-time.

  The blog post concludes by presenting the finalized interactive animation, embedded within the page, enabling readers to experiment with different slug placements and directly observe the resulting paths. This visualization effectively illustrates the non-intuitive nature of shortest paths on a three-dimensional surface and provides a tangible, engaging way to explore the underlying mathematical principles. The author also briefly touches upon potential extensions and future directions for the project, suggesting the possibility of incorporating different geometries beyond the cube.

  • slugs
  • cube
  • animation
  • interactive
  • interactive animation
  • Simulation
  • 3d
  • graphics
  • WebGL
  • javascript
  • blog
  • gingerbeardman

  Summary of Comments ( 4 )
  https://news.ycombinator.com/item?id=42731588

  Verbose tl;dr

  HN users generally enjoyed the interactive animation and its clean, minimalist presentation. Several commenters explored the mathematical implications, discussing the paths the slugs would take and whether they would ever meet given different starting positions. Some debated the best strategies for determining collision points and suggested improvements to the visualization, such as adding indicators for past collisions or allowing users to define slug speeds. A few commenters also appreciated the creative prompt itself, finding the concept of slugs navigating a cube intriguing. The technical implementation was also praised, with users noting the smooth performance and efficient use of web technologies.

  The Hacker News post titled "Slugs on a Cube: An Interactive Animation" has generated several comments discussing the linked blog post's interactive demonstration of slugs navigating a cube.

  Several commenters express appreciation for the visualization and its educational value. One user highlights the clear way it demonstrates how connectedness influences pathfinding, specifically mentioning how counterintuitive it can be to trace paths on a 3D object unfolded into 2D. Another commenter appreciates the interactive element, allowing for experimentation and a deeper understanding of the concept. The simplicity and effectiveness of the animation are praised, with one user calling it a "nice little visualization."

  The discussion also delves into the mathematical underpinnings of the problem. One commenter connects the concept to graph theory and mentions the challenge of pathfinding on complex shapes. Another user discusses the broader implications of this type of visualization for understanding networks and routing.

  Some commenters offer suggestions for expanding the demonstration. One proposes allowing users to define their own starting and ending points for the slugs. Another suggests exploring different 3D shapes beyond the cube. A third user mentions the potential of adding obstacles to the cube's surface to further complicate the pathfinding problem.

  Finally, some comments touch upon related topics. One user draws a parallel to the game HyperRogue, which features non-Euclidean geometry. Another mentions the concept of "unwrapping" 3D shapes into 2D, and the challenges involved in that process.

  In general, the comments reflect a positive reception of the interactive animation, praising its clarity and educational value, while also sparking further discussion about the underlying mathematical concepts and potential extensions of the project.

• A Raycaster in Bash

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  Posted: 2024-12-20 22:25:45

  Verbose tl;dr

  This project demonstrates a surprisingly functional 3D raycaster engine implemented entirely within a Bash script. By cleverly leveraging ASCII characters and terminal output manipulation, it renders a simple maze-like environment in pseudo-3D. The script calculates ray intersections with walls and represents distances with varying shades of characters, creating a surprisingly immersive experience given the limitations of the medium. While performance is understandably limited, it showcases the flexibility and unexpected capabilities of Bash beyond typical scripting tasks.

  This GitHub repository, titled "pseudo3d," showcases a remarkably concise implementation of a raycasting engine written entirely in Bash script. The provided code leverages the shell's built-in string manipulation capabilities and arithmetic functionalities to render a pseudo-3D perspective of a simple world map defined within the script itself. The world map is represented as a two-dimensional array of characters, where different characters signify different types of walls or empty space.

  The core of the raycasting algorithm involves iterating through the screen's horizontal pixels, calculating the viewing angle for each pixel based on the player's position and viewing direction. For each pixel, a "ray" is cast from the player's position into the world map, effectively tracing a line until it intersects with a wall character. The distance to the wall intersection is then calculated using a simplified distance formula.

  This distance value determines the height of the wall segment to be drawn on the screen for that particular pixel. Closer walls result in taller wall segments, creating the illusion of perspective. The rendering process utilizes ANSI escape codes to directly manipulate the terminal output, drawing vertical lines of varying heights representing the walls. Different wall characters in the map are visually distinguished by using different colors for the rendered wall segments, again achieved through ANSI escape codes. The rendering process updates the terminal output in real-time, providing a dynamic view as the player navigates the world.

  The player's movement and rotation are handled through basic keyboard input. The script detects specific key presses, updating the player's position and viewing angle accordingly. This dynamic update combined with the real-time rendering loop creates an interactive experience where the player can explore the defined world from a first-person perspective. While rudimentary, the implementation successfully demonstrates the fundamental principles of raycasting in a surprisingly minimal and accessible manner using the Bash scripting environment. The code's brevity and reliance on built-in shell functionalities serve as a testament to the versatility and unexpected capabilities of the Bash scripting language beyond typical system administration tasks.

  • bash
  • raycasting
  • raytracer
  • 3d
  • pseudo3d
  • rendering
  • graphics
  • cli
  • command-line
  • shell
  • Linux
  • unix
  • ASCII
  • Text-based
  • gamedev
  • game-development
  • programming
  • opensource
  • pseudo-3D
  • Game Development
  • Open Source

  Summary of Comments ( 34 )
  https://news.ycombinator.com/item?id=42475703

  Verbose tl;dr

  Hacker News users discuss the ingenuity and limitations of a bash raycaster. Several express admiration for the project's creativity, highlighting the unexpected capability of bash for such a task. Some commenters delve into the technical details, discussing the clever use of shell built-ins and the performance implications of using bash for computationally intensive tasks. Others point out that the "raycasting" is actually a 2.5D projection technique and not true raycasting. The novelty of the project and its demonstration of bash's flexibility are the main takeaways, though its practicality is questioned. Some users also shared links to similar projects in other unexpected languages.

  The Hacker News post titled "A Raycaster in Bash" (https://news.ycombinator.com/item?id=42475703) has generated several comments discussing the project, its performance, and potential applications.

  Several commenters express fascination with the project, praising the author's ingenuity and ability to implement a raycaster in a language like Bash, which isn't typically used for such computationally intensive tasks. They admire the technical achievement and the demonstration of what's possible even with limited tools.

  Performance is a recurring theme. Commenters acknowledge that the Bash implementation is slow, with some sharing their own experiences and benchmarks. Suggestions are made for potential optimizations, including using a different shell like zsh for potential performance gains, leveraging awk, and exploring alternative algorithms. The inherent limitations of Bash for this type of application are recognized, and the discussion explores the trade-offs between performance and the novelty of the implementation.

  The practical applications of the project are also debated. While some view it primarily as a technical demonstration or a fun experiment, others suggest potential use cases where performance isn't critical. One commenter proposes using it for generating simple visualizations in constrained environments where other tools might not be available.

  The choice of Bash itself is discussed. Some commenters question the rationale behind using Bash, suggesting more suitable languages for such a project. Others defend the choice, highlighting the value of exploring unconventional approaches and pushing the boundaries of what's possible with a familiar scripting language. The discussion touches upon the educational aspects of the project and its potential to inspire creative solutions.

  Beyond the technical aspects, there's appreciation for the author's clear and well-documented code. The readability and organization of the project are commended, making it easier for others to understand and learn from the implementation. The project is also seen as a testament to the flexibility and power of Bash, even beyond its typical use cases. Some commenters express interest in exploring the code further and potentially contributing to its development.