My simulation creates a 2d grid of vectors and scalars (EDIT of velocity, depth etc), at 60 frames per second. Is it correct? It looks sort of right... but who knows?How can I tell what's happening - especially for debugging?Thoughts so far:Arrows for velocity field is difficult to see what's happening in small areas/fine detail. And if using length for magnitude, you have to get the scale right, or the arrows disappear (too small) or become lines (too big).Or, can use colours for magnitude (standard rainbow key, to map colours to numbers). Still has the scaling problem.particles (dots), evenly placed and moved by the velocity field. Density of dots then implies divergence; and cirlcular motion implies vorticity.Green/red for curl (vorticity), clockwise/counter-clockwiseGrey-scale for divergence (compression)Height field as a 3d isometric surface, with labelled axes and scalesIs it better to dump all the data to a file/s, and then visualize it later, with a separate tool? You could then move forward and backward in time, like a movie, and switch between quantities to visualize, and methods of visualizing. Maybe, in practice, just hacking the code to display different things is the best way to make progress?I'll have to create the visualization code myself, and it seems a bit of a project in itself, so I'm hesitant. I'd like to get some guidance from those more experienced, as to what is actually most useful, before diving in.what quantities are most useful to visualize?    how to display them?    how (and when) to select which one to display (a UI issue)?EDIT I should add, I'm developing on android (on the device itself, not on a PC), so many popular tools/apps aren't available. And, since my main project is to display real-time simulation, also visualizing some data isn't that different a task.
In practice, what are the most useful ways to visualize 2d fluid flow, to tell what is happening in the simulation? Esp for verification and debugging
fluid dynamics;visualization;data visualization;verification