Hi,
You're correct. TDE uses Cinemachine, which keeps a tight grip on camera control. Instead of using Zoom2D, control Cinemachine. First import the Dialogue System's Third Party Support / Cinemachine Support unitypackage.
Cinemachine uses components called Cinemachine Virtual Cameras (vcams for short) that define how the camera should work (e.g., follow targets, zoom in on a location, etc.). Each vcam has a Priority value. Cinemachine uses the vcam that has the highest Priority. TDE's Koala Dungeon scene has a vcam named "CM vcam1" with a Priority of 10.
You can add another vcam to the scene that focuses on the NPC. Give it a Priority of 0 so Cinemachine doesn't use it during regular play. When the conversation starts, increase its Priority to something higher than 10.
There are two ways you can control a vcam's Priority in a conversation:
1. Add a
Cinemachine Priority On Dialogue Event component to the NPC. Set the dropdown to OnConversation. Assign the vcam.
2. Or use the
CinemachinePriority() sequencer command.
You can use both. For example, use Cinemachine Priority On Dialogue Event to prioritize a vcam that focuses on the NPC at the start of the conversation. Say the NPC points to a mysterious object that she wants the player to investigate. Use CinemachinePriority() to prioritize a different vcam that focuses on the mysterious object. Later, use another CinemachinePriority() to drop the priority of the mysterious object vcam. This will cause the NPC's vcam to take effect again.
