In Section 2.1 of the first part of his two-part paper "Suitable Extender Models" Woodin states the following result as Theorem 5:
Suppose that $\delta$ is a limit of Woodin cardinals and that $T$ is a tree on $\omega\times\kappa$ for some $\kappa$. Then the following are equivalent.
(1) $T$ is $(<\delta)$-weakly homogeneous. (2) There is a tree $S$ on $\omega\times\delta$ such that for all $\mathbb{P}\in V_{\delta}$, if $G\subseteq\mathbb{P}$ is $V$-generic then in $V[G]$,
$$p[T]=\mathbb{R}^{V[G]}\setminus p[S]. $$
This result doesn't seem to be stated in the set of notes "The Stationary Tower". I was wondering if anyone knew a reference for it.
The perfect reference for this is
A preprint can be accessed from John Steel's website. If you are not already familiar with universally Baire sets, then I also recommend you read the original reference (mentioned by Asaf in a comment), mainly because it is beautiful mathematics, but John's paper is self-contained and addresses this result explicitly.