Fluid simulation · gemini-3-flash-preview
Create a real-time fluid simulation on a full-screen canvas where dragging the mouse pushes swirling colored dye through the fluid.
transcript · 4 messages
Create a real-time fluid simulation on a full-screen canvas where dragging the mouse pushes swirling colored dye through the fluid.
thinking
**Developing Fluid Simulation** I'm focusing on creating a self-contained, full-screen fluid simulation within a single HTML file. The current plan involves implementing a canvas-based rendering system and integrating mouse interaction for dynamic swirling effects. **Implementing Grid-Based Simulation** I'm refining the core simulation, leaning towards a simplified grid-based approach, likely a variation of Jos Stam's Stable Fluids. The focus is on achieving a real-time Eulerian fluid simulation on a canvas, incorporating advection, projection, and mouse input for dynamic effects. **Exploring WebGL Rendering** My thoughts are now centered on leveraging WebGL for fluid simulations due to performance concerns with pixel-by-pixel canvas rendering. This necessitates crafting custom shaders for advection, divergence, pressure, and projection, alongside direct density/velocity addition and final rendering.
index.html (16791 bytes)Successfully wrote 16791 bytes to index.html
thinking
**Refining Fluid Simulation** I'm currently deep in refining the WebGL fluid simulation. My focus is on optimizing the advection and projection steps, particularly the Jacobi iterations for pressure, ensuring a smoother and more stable output. I'm also tweaking interaction parameters for more intuitive splatting. **Verifying Initialization Logic** I'm reviewing the setup, ensuring the position and index buffers are correctly initialized before the `blit` operation. This step is crucial for passing vertex data to the shaders and maintaining the integrity of the simulation's grid operations. My recent focus has been on this foundational aspect. **Verifying Shader Uniforms** I'm confirming that `texelSize` is correctly applied across all relevant shaders, especially the `baseVertexShader`, when that program is active. I've noted that the uniform location needs to be fetched and set for each program that utilizes it, not just the `advectProgram`. **Confirming Texture Units** I'm double-checking how texture units are managed, specifically ensuring that when I access something like `velocity.read.texture`, the correct unit is implicitly or explicitly assigned. This is vital for preventing texture binding conflicts and ensuring data is read from the intended sources across different shader programs.
The real-time fluid simulation has been implemented in a single self-contained `index.html` file using WebGL for high performance. It features: - **Navier-Stokes equations** solver (Stable Fluids) for realistic swirling motion. - **Dye advection** and **velocity diffusion** computed on the GPU. - **Interactive input**: Moving the mouse or touching the screen "pushes" the fluid and injects colored dye. - **Full-screen responsive design**: The simulation automatically adjusts to window resizing. - **Dynamic colors**: The dye color changes slightly on each click/touch. The simulation uses a multi-pass shader approach: 1. **Advection**: Moving dye and velocity along the fluid's own velocity field. 2. **Splatting**: Adding localized forces and density from user interaction. 3. **Divergence & Pressure**: Computing the incompressibility of the fluid using Jacobi iterations. 4. **Gradient Subtraction**: Applying the resulting pressure to update the velocity field. You can run this by opening `index.html` in any modern web browser. ```html <!-- index.html is present in the current directory --> ```
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
EVALUATION
Fluid dye trail appears and swirls only with drag, but click/idle stays blank with no dye injection otherwise.
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.