6. Given $O$ as a fixed point on the plane of $\triangle A B C$, a moving point $P$ satisfies $\overrightarrow{O P}=\overrightarrow{O A}+\lambda\left(\frac{\overrightarrow{A B}}{|\overrightarrow{A B}|}+\frac{\overrightarrow{A C}}{|\overrightarrow{A C}|}\right)$, where $\lambda \in[0,+\infty)$, then the trajectory of point $P$ is $\qquad$ .
Find the angle bisector of $\angle B A C$.
Parse by
$$
\overrightarrow{O P}=\overrightarrow{O A}+\lambda\left(\frac{\overrightarrow{A B}}{|\overrightarrow{A B}|}+\frac{\overrightarrow{A C}}{|\overrightarrow{A C}|}\right) \Rightarrow A P=\lambda\left(\frac{\overrightarrow{A B}}{|\overrightarrow{A B}|}+\frac{\overrightarrow{A C}}{|\overrightarrow{A C}|}\right)
$$

and $\lambda \in[0,+\infty)$, so $\lambda\left(\frac{\overrightarrow{A B}}{|\overrightarrow{A B}|}+\frac{\overrightarrow{A C}}{|\overrightarrow{A C}|}\right)$ represents a vector on the angle bisector of $\angle B A C$. Therefore, the locus of point $P$ is the angle bisector of $\angle B A C$.