Create underwater

Hello i have question, in panda3d sample i found example for add water, but panda3d have sample of water with underwater ?
or it’s possible in panda3d to add underwater environnement ?
Maybe i must to change camera color for add blue filter, play water sound and update physic but how to detect in game if i’m in earth or underwater and update physic ?
panda3d (with bullet ?) can be support multi-physic for create a world with earth gravity, underwater gravity and space gravity (disable gravity ?)

Regarding detection of water, how you go about that might depend on how detailed a simulation you want. Is it enough that all regions below a “water level” to be “underwater”? Or are only some areas “underwater”? Do you have non-standard water, like water that clings to the ceiling, or that floats about?

If a simple “water-level” is enough, then you might just add logic that check’s the player’s z-coordinate, and respond when the player moves above or below that level.

If you have a more complex system in mind, then perhaps triggers (using the physics system) might work.

Regarding physics, if you’re using Bullet then I seem to recall that it allows you to specify gravity on a per-object basis, which seems as though it should allow for various levels of gravity. See here for more information. There may be other approaches, too.