Render tiles' properties like NetLogo

[smarianimore]

Dear devs,
in Netlogo you can assign properties to patches and then color patches, and in general change their appearance in some ways (e.g. their color)

We are not finding an easy way to do in MESA.

We know that we can add properties to tiles with property layers, but we are having trouble rendering those properties in a graphic way.

For instance, what if we want to create a maze with walls? We'd like to visualize walls by colouring them.
What if we want to color the tiles differently based on some properties?
We browsed the code and the documentation but did not find anything at the moment...

For agents there is a function you can pass to render them, but for tiles you can only pass a static dictionary, not a function to update their rendering...

Are we missing something?

[quaquel]

You are absolutely right that the support for visualizing property layers is quite limited and restricted. In #2642, we have touched on this as well.

Note that it is always possible to write your own fully custom space visualization method. We don't have a good example showcasing this, but it is possible. SolaraViz takes a list of components as arguments. You can make your own @solara.component. You could take SpaceMatplotlib (assuming you want to use matplotlib) as your template if you want to go down this route.

For ease of reference, you can find SpaceMatplotlib below. In short, its a method that takes the model as argument and returns a solara.FigureMatplotlib instance.

@solara.component
def SpaceMatplotlib(
    model,
    agent_portrayal,
    propertylayer_portrayal,
    dependencies: list[any] | None = None,
    post_process: Callable | None = None,
    **space_drawing_kwargs,
):
    """Create a Matplotlib-based space visualization component."""
    update_counter.get()

    space = getattr(model, "grid", None)
    if space is None:
        space = getattr(model, "space", None)

    fig = Figure()
    ax = fig.add_subplot()

    draw_space(
        space,
        agent_portrayal,
        propertylayer_portrayal=propertylayer_portrayal,
        ax=ax,
        **space_drawing_kwargs,
    )

    if post_process is not None:
        post_process(ax)

    solara.FigureMatplotlib(
        fig, format="png", bbox_inches="tight", dependencies=dependencies
    )

[smarianimore]

Thanks @quaquel for the quick reply :)
Apparently thus there is no easy "fix" on your side nor a short-term plan to address this...?

If we wanna go down the path of the custom Solara component, my intuition given your snippet is that we would need to either

1. redefine method draw_space to render property layers in a custom way
2. add post processing steps by redefining the homonym method or adding code

In case of 1, I see there is already propertylayer_portrayal as argument: what is this?

General question about the rendering process: my intuition is that at every simulation step the method you posted is called to re-draw from scratch the space?

Thanks for your assistance :)

[quaquel]

I doubt it will be addressed in the next stable release. We are all volunteers. I have ideas on this but am rather busy with teaching and my normal academic tasks. It might be only in summer I have time to look at this myself again.

I think you can keep it simpler. Something like the code below should be sufficient I think. In essence, the components are just callables that take model as their only argument. The additional keyword arguments shown above are just passed on from the SolaraViz call, so propertylayer_portrayal is the dict you mentioned in the starting post. And yes, at each step the function shown below is called.

@solara.component
def my_own_space_drawer(model):
    update_counter.get()
    space = model.space

    fig = Figure()
    ax = fig.add_subplot()

    # use mesa to just draw the agents
    mesa.visualization.draw_space(
        space,
        agent_portrayal,
        ax=ax,
    )  

    # here put your own custom matplotlib stuff based on propertylayers

    solara.FigureMatplotlib(
        fig, format="png", bbox_inches="tight", dependencies=dependencies
    )

[smarianimore]

We are all volunteers

We're all on the same boat :)
Normally I would fire a PR but i am in my worst teaching semester now...

Ah I got it now (I think): I don't need to modify your component as I can add any one I'd like.
Ok, if we manage to find the time we will play with this a bit and maybe issue a PR if something meaningful and not too hacky comes out

Thanks! Will get back if we have issues.

[quaquel]

I'll keep this issue open.

It would be good to update one of the advanced examples to showcase how to do this for future reference.