oneshotlm
Compare all models on this prompt →

Bouncing balls in a heptagon · gpt-5.4-nano

Show 20 numbered balls (1 to 20) dropping from the center of a heptagon that spins 360 degrees every 5 seconds. The balls are affected by gravity and friction, collide with each other, and bounce realistically off the rotating walls; show each ball's spin via the rotation of its number. Implement all collision detection yourself.

⛨ sandboxed Open in new tab ↗
transcript · 10 messages
user

Show 20 numbered balls (1 to 20) dropping from the center of a heptagon that spins 360 degrees every 5 seconds. The balls are affected by gravity and friction, collide with each other, and bounce realistically off the rotating walls; show each ball's spin via the rotation of its number. Implement all collision detection yourself.

assistant
thinking
**Explaining spin visualization**

I'm planning to spawn small radial offsets along a circle to prevent overlap, keeping them within a smaller radius. I might start from the center with slight jitter to add randomness. For the spin visualization, each ball will have its own angular orientation angle, and I'll draw the circle while rotating the numbers by the angle. I'll use ctx.save to translate and position correctly, then draw the text aligned to the center. I'll also show the spin direction and calculate the angles for the rotating walls.**Resolving ball and wall collision**

I'm considering how to resolve the collision between the ball and the wall by using relative velocity and impulse. I'll approximate the wall as having infinite mass, which means it can only rotate. The impulse will account for the wall's effective mass and include restitution. For collision detection, I'll compute the overlapping edges and contact points, determining the wall's velocity at the point of contact. After calculating the relative velocity, I'll apply impulses to adjust the ball's velocity and account for tangential friction as needed.**Updating disk collision calculations**

When considering a disk colliding with a fixed wall, I need to account for the rotational contribution using the formula r^2/I, which simplifies to 2/m. This gives me an effective denominator of 3/m for impulse calculations. I can compute the tangential impulse, ensuring I clamp it within the friction limits. The impulse vector will combine both normal and tangential components, and then I’ll update the ball's linear and angular velocities based on the contact point's position, which is determined by the normal vector from the disk's center to the wall.**Resolving collision mechanics**

For the collision resolution, I’ll calculate the rotational change using cross products and get Δω from crossZ over the moment of inertia, I. To prevent penetration, I need to move the ball's center outward based on the penetration depth calculated. For segment detection, if the distance between the ball center and closest point is less than the radius, I'll adjust the center accordingly. I also have to consider edge collision detection for each segment and ensure the balls stay inside the polygon while performing necessary checks efficiently.**Crafting collision and rendering plan**

I’m planning the collision mechanics involving friction and applying it to the ball's tangential velocity after a collision. For rendering, I'll draw the rotating heptagon walls and the balls with gradients. The HTML needs to be responsive with a full-screen canvas. My implementation plan includes defining constants, initializing physics variables, and calculating collisions based on distance and angles. I'll ensure proper handling of ball-ball and ball-wall interactions, accounting for impulses and angular changes. Position corrections will follow collisions, and I’ll render each frame with updated states.**Calculating impulse and corrections**

I’m calculating the tangential impulse and clamping jt within a defined range based on the normal impulse magnitude. After that, I’ll combine these impulses to update the velocities and angular velocities for both objects involved. For positional corrections due to overlaps, I plan to adjust their positions along the normal vector. I’ll ensure to apply restitution and corrections to prevent repeated collisions, using smaller time steps and multiple iterations for wall interactions. Now, I’m ready to start coding by writing the index.html file.
write index.html (14352 bytes)
toolResult

Successfully wrote 14352 bytes to index.html

assistant
bash {"command":"node -e \"const fs=require('fs');console.log(fs.readFileSync('index.html','utf8').includes('resolveBallBall'))\""}
toolResult

true

assistant
bash {"command":"python3 - <<'PY'\nimport re\ns=open('index.html','r',encoding='utf8').read()\nprint('size',len(s))\n# quick syntax check by runn
toolResult

/bin/bash: line 1: python3: command not found Command exited with code 127

assistant
thinking
**Checking syntax with Node.js**

I'm not using Python here. Instead, I'll utilize Node.js to check the syntax of the extracted script. My plan is to write a quick command in Node to validate the syntax directly from the file, using regex. I'll be executing this through bash with Node. It feels like a straightforward approach, and I'm curious to see how it turns out! I'll ensure I follow the right steps to get accurate results.
bash {"command":"node - <<'NODE'\nconst fs=require('fs');\nconst html=fs.readFileSync('index.html','utf8');\nconst m=html.match(/<script>([\\s\\S
toolResult

return 0

assistant

Created a single self-contained **`index.html`** web app that simulates **20 numbered balls (1–20)** dropping from the **center of a rotating heptagon**. The heptagon rotates **360° every 5 seconds**, balls undergo **gravity + friction**, **collide with each other**, and **bounce realistically off the rotating walls**. Ball spin is shown by rotating each ball’s number. File: **`/workspace/index.html`**

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

modelgpt-5.4-nano
vendorOpenAI
harnesspi-agent
generated2026-07-22

EVALUATION

3/5 working

Heptagon spins with 20 numbered balls settling under gravity, but no visible response to click/drag/wheel/keyboard input.

Vision grade · anthropic/claude-sonnet-5

MEASUREMENTS

Raw readings from the capture, not a verdict — the grade above is the only judgement. Percentages are how much of the screen changed; the measure under-reports sparse motion on a dark background.

idle motion6.3%
on click6.1%
on drag6.3%
on wheel6.3%
on enter + space6.2%
on arrow keys6.2%
on w/a/s/d6.1%
frame spread16.8 / 255
console errors0
js errors none

METRICS

runtime80.3s
tokens in10k
tokens out9.4k
cached17k
cost / run$0.0141