Things are starting to get interesting! I spent the last few hours adding a velocity vector field to the grid. Now, instead of just bleeding outward uniformly, the dye actually gets carried by the current. I had to wrap my head around advection, which took some debugging, but mapping the mouse movement to generate directional forces totally changed the feel. When you drag the cursor, it pushes the fluid around, creating these cool, swirling patterns. It’s still just grid-based colors, but it finally behaves like a real liquid. Can’t wait to drop actual particles into this current!