Fluid simulation · qwen3.6-35b-a3b
Output generated Cost / run $0.0048 Runtime 68.1s
Prompt for this run
Build an interactive 2D fluid-and-dye simulation on a full-screen canvas. Use HTML, CSS, and JavaScript as needed. Write it to `index.html` in the current working directory using your file tools. Inline your own CSS and JavaScript. Do not use external assets, CDNs, or network requests. No third-party libraries are provided. Required behavior: - Maintain a velocity field and a colored dye field. Advect dye through the moving fluid so it forms persistent swirling flow; a collection of independent fading particles is not sufficient. - Dragging injects dye and momentum in the drag direction. Momentum and dye remain visible after the pointer is released and gradually dissipate. Approximate fluid behavior is acceptable; choose the numerical method and Canvas 2D or WebGL implementation. - Seed the initial scene with a small amount of colored dye and motion so the simulation is visible on load. - Provide a color selector, Pause/Resume, and Clear. Clear removes dye and resets velocity; the next drag can start a new flow. - Bound simulation resolution and work per frame so controls remain responsive at a 1200 by 800 viewport. Verify: Drag through the canvas and sample the flow after release. Check that dye follows the drag, continues swirling, and responds to a second drag in another direction. Use Clear, then drag again to check that a fresh flow can start.
TAKE IT TO CODE
A single self-contained HTML file — copy it and open in any browser, or reuse the prompt with your own pi-agent run.
RUN
METRICS
Transcript · 7 messages
Build an interactive 2D fluid-and-dye simulation on a full-screen canvas. Use HTML, CSS, and JavaScript as needed. Write it to `index.html` in the current working directory using your file tools. Inline your own CSS and JavaScript. Do not use external assets, CDNs, or network requests. No third-party libraries are provided. Required behavior: - Maintain a velocity field and a colored dye field. Advect dye through the moving fluid so it forms persistent swirling flow; a collection of independent fading particles is not sufficient. - Dragging injects dye and momentum in the drag direction. Momentum and dye remain visible after the pointer is released and gradually dissipate. Approximate fluid behavior is acceptable; choose the numerical method and Canvas 2D or WebGL implementation. - Seed the initial scene with a small amount of colored dye and motion so the simulation is visible on load. - Provide a color selector, Pause/Resume, and Clear. Clear removes dye and resets velocity; the next drag can start a new flow. - Bound simulation resolution and work per frame so controls remain responsive at a 1200 by 800 viewport. Verify: Drag through the canvas and sample the flow after release. Check that dye follows the drag, continues swirling, and responds to a second drag in another direction. Use Clear, then drag again to check that a fresh flow can start.
thinking
The user wants me to build a full-screen 2D fluid simulation with dye, all in a single index.html file. Let me build this step by step: 1. A grid-based fluid simulation (Navier-Stokes approximation) 2. Velocity field (u, v components) 3. Dye/color field (rgba) 4. Advection - move dye through the velocity field 5. Mouse interaction - inject dye and momentum 6. UI controls - color selector, Pause/Resume, Clear 7. Initial conditions with some dye and motion I'll use a grid-based approach (like Jos Stam's "Stable Fluids") with a lower resolution grid for performance, upscaled to the full canvas. Let me write the complete implementation: - Use a grid resolution (e.g., 128x85 or similar) - Implement: diffuse, advect, project (pressure solve) - Use WebGL for the simulation (multiple render targets for the fields) - Or use Canvas 2D with ImageData Actually, since we can't use external resources, let me use a Canvas 2D approach with ImageData. This is simpler but still looks good. Let me think about the approach: - Use a lower resolution grid (maybe 128x85 or 150x100) - Simulate on that grid - Render by scaling up to the canvas For the fluid simulation: - Velocity field (u, v) - Color/dye field (r, g, b, a) - Steps: advect velocity, advect color, diffuse, project (make divergence-free) I'll implement this with a grid-based solver using Canvas 2D ImageData. Let me write a comprehensive implementation.
/tmp/job-RWcvVu/index.html (13108 bytes)Successfully wrote to /tmp/job-RWcvVu/index.html
thinking
Good, the file is written. Now let me inspect it in the browser to verify the simulation works correctly.
{"action":"screenshot"}Frame 1, +0ms
[Browser image supplied to model]
{"console":["warning: An iframe which has both allow-scripts and allow-same-origin for its sandbox attribute can escape its sandboxing."],"dom":"Color\nPause\nClear\nClick & drag to paint flow","images":"attached"}
thinking
The simulation is working! I can see: 1. Initial dye is seeded - there's a large white circle (dye) and some smaller blobs 2. The canvas is full-screen with controls at the top (Color, Pause, Clear buttons) However, I notice the initial dye appears white/light instead of colored. Let me check if the simulation is actually working correctly by looking at the code. The dye should be colored, not just white. Also, I need to verify that dragging injects proper momentum and dye with the selected color. Let me read the file to check the implementation quality and fix any issues. The initial dye appears white/light, which suggests the dye field initialization might be using grayscale values (R=G=B=max). Let me read the file to check and fix the initialization colors and any other issues.
The simulation is rendering with initial dye, but it appears as white/bright blobs rather than colored dye. Let me read the file to check the implementation and fix issues. <tool_call> <|im_start|>user <tool_call> <|im_start|>user {"pid":4497,"browser_stderr":"","stdout":""}