Quality regression: generated visualizations are subpar and broken

Start by reviewing the agent system prompt, the widget renderer import map, and the LangGraph/CopilotKit setup around langchain_openai.ChatOpenAI. Compare the attached .chalk HTML outputs across models and broader visualization prompts, then determine whether prompt guidance, few-shot examples, or model changes address the regression. Done means the cause is identified and a reproducible quality improvement is demonstrated.

Problem

The quality of generated visualizations from the deployed agent has degraded. The same prompt ("sphere icosahedron morph") produces broken or low-quality outputs across multiple attempts.

Evidence

Two downloaded outputs from the same prompt attached as .html files in .chalk/:

Attempt 1 — CSS 3D divs (sphere-icosahedron-morph (1).html)

• Uses 20 <div> elements with CSS transform-style: preserve-3d and clip-path transitions
• No WebGL / Three.js despite it being available via the import map
• Hover interaction conflicts with the CSS spin animation (style.animation = 'none' vs CSS animation: spin 10s)
• The morph is cosmetic — just toggling border-radius: 50% ↔ clip-path: polygon() on flat divs
• Faces positioned via manual JS math that approximates 3D but doesn't actually render proper geometry

Attempt 2 — Canvas 2D fake 3D (sphere-icosahedron-morph.html)

• Uses canvas.getContext('2d') instead of WebGL
• Sphere is just a radial gradient circle, not actual geometry
• Icosahedron faces are projected triangles drawn with ctx.moveTo/lineTo — no real lighting
• Uses color-mix() CSS which has mixed browser support
• The "morph" is interpolating between a gradient blob and wireframe triangles — visually unconvincing

What a good output would look like

• Use Three.js (available in the import map at https://esm.sh/three)
• Proper IcosahedronGeometry with MeshStandardMaterial or custom shaders
• Real WebGL lighting and smooth vertex-level morphing between sphere and icosahedron
• Orbit controls or smooth auto-rotation

Possible causes

1. Model regression — GPT-5.4 (gpt-5.4-2026-03-05) may be producing lower-quality code for complex 3D visualizations compared to earlier versions
2. System prompt lacks quality guidance — The current prompt mentions widgetRenderer capabilities but doesn't guide the model toward using Three.js/WebGL for 3D content, or set quality expectations for interactive visualizations
3. No few-shot examples — The agent has no reference for what "good" output looks like, so it falls back to simpler CSS/Canvas approaches

Suggested investigation

• Compare output quality between GPT-5.4 and other models (e.g. Claude) for the same prompts
• Add quality guidance to the system prompt (e.g. "For 3D visualizations, use Three.js from the import map")
• Consider adding few-shot examples of high-quality widget HTML in the agent skills
• Test a broader set of prompts to determine if regression is model-wide or specific to 3D content

Environment

• Model: gpt-5.4-2026-03-05 via langchain_openai.ChatOpenAI
• Agent: LangGraph with CopilotKit middleware
• Widget renderer: sandboxed iframe with import map (Three.js, GSAP, D3, Chart.js available)