WebHeat lets you drop in any STL file and watch heat propagate through it like gossip through a small town. The workflow splits cleanly: first you set up your geometry and materials, then you flip to simulation mode and the whole thing transforms into a thermal heatmap rendered from GPU-computed textures. Voxels fill the object's bounding box, each one inheriting properties from whatever geometry intersects it. Empty space gets air. Everything else gets physics.

The technical backbone here is solid. A compute shader handles the heavy lifting, ping-ponging between two buffers so you never accidentally read from what you're writing to. The voxelized space ships to the GPU alongside material properties, and the shader spits out a texture that maps directly to the spatial dimensions. If you want the actual math, there's a PDF in the repo that walks through the thermal computation in proper detail.

Here's the part that makes this worth paying attention to: Raziel Moesch is a high school senior. He picked up Newton's law of cooling while presenting on thermal energy for a class, got curious, and a few weeks later decided to build something impressive for internship applications. He initially considered OpenGL but pivoted to WebGPU so the whole thing could run as a browser demo. Smart call. You can find the full source on GitHub. Worth poking around. Or just throw your favorite STL at it and see what melts first.