Need help finding a movie title plz - another live action + animation

10% live action 90% cartoon:

an older teenager or possibly 20 something year old- live action - who used a seemingly regular paintbrush to paint a world and was then transported to that world where he became a cartoon, there seemed to be some kind of flood. Maybe it was raining really hard in the made up world or something. Anyway, when the water subsided, he found himself in a kind of forest and there was some kind of innocent creatures who told him about the world that he was in...

There were several kings. There was a Sea King who had a water bed made out of some clear material with actual fish and seahorses and stuff floating around in it.

And there was an evil king who had guards that looked like long axes or halberds... anyway. He had this machine that was destroying the forest, he'd imprison or possibly kill the innocent creatures.... somehow the paint brush guy managed to rig his machine to where it all became good and made flowers and he became a good king instead, everyone living happily ever after and all that. I think once he defeated the bad king, he may or may not have gone back to his own world - live action.

Any help or suggestions are massively appreciated.