They walked out of the ark and into a new world. Noah and his family alone were saved from the flood’s destruction. Noah built an altar and offered burnt sacrifices, humbly acknowledging the power and protection of the God of all creation.
There was (or should have been) with all of them a deepened understanding of God’s righteousness, and his righteous expectation for their lives. He established a new covenant with them, one that required a respect for human life as made in God’s image.
When Ham told his brothers about their father lying naked in the tent in a drunken stupor, he must have done so in a way that was highly disrespectful and offensive. We don’t know what God thought of Noah’s actions, but Ham’s actions must have violated the spirit of this new covenant, because the judgment was severe.
