I was recently asked to give a brain dump of knowledge I've learn over the many years of creating ingame cinematics. One area I can not stress enough importance on is how a cinematic is started during gameplay and how is gameplay returned. The smoothest flowing cinematic games spend a great deal of time looking at this one aspect and it sticks out when a production doesn't focus on this careful handoff. Here's some examples of how you can address this handoff. This is but a few examples of many possibilities but will hopefully get the gears turning on how you can solve your scenes flow with the gameplay around it.
What comes before a scene, what comes after? What’s the game designer planning on doing around the scene? How do we trigger a scene, how do we leave it? What are we looking at before the scene starts? Is the scene on a timed start, is it player triggered, is it an area trigger, is it a trigger on an object like clicking on a door? Thinking about these questions and more will allow you to create seamless and smooth transitions from gameplay to the cinematic and back again.
You have a scene that follows combat. It is triggered when the last enemy has been killed off. Start into our scene as the last guy drops, mid fall to the ground. You want that tie in through the death animation. If your game is a 3rd person camera, you want to go to a camera that isn’t a medium shot and isn’t behind your character.
Your scene is triggered as you enter a room. If you’re clicking on the door to trigger the scene, you can start the camera on the inside of the room, preferably showing the door opening and your party entering.The audience will put two and two together that what you're seeing is on the other side of the door we just clicked on. If you're running up to the door and the scene is triggered before you get to it. You may want to show the player and party approaching the door. That’s easily done through an OTS shot following your player, however if the game is a 3rd person then that will feel like a jump cut, so you need to design different shots to work your way into that room. In a case like this I might go to the designer and ask if the scene can be triggered on touching the door which is probably a straightforward change for him, and saves the cinematics team a day or two of extra shot work.
Your scene ends into combat. If it’s a shooter you want to design your cinematic so that the player moves into a cover position so that he doesn’t get mowed down as gameplay resumes. Be mindful of the game camera so that your last shot isn’t an OTS. Maybe your game doesn’t cut back to gameplay, instead it blends. Now you need to plan for that seamless move. If it blends then you want to work your camera into the game camera position in which case an OTS shot is perfect for this. Hopefully in your mocap recording you’ve matched the gameplay pose that follows. A lot of time can be eaten up working a mocap action into the correct pose.
You might have a situation where the player can be anywhere when the scene starts, it could be easily fixed by having a couple of shots without the player to start then show him/her walking into the scene. You could design the scene so that the first few shots are customized to the players location. You could also try to solve this with gameplay, working with the designer to funnel the player into a more confined location.
There could be a variable set of conditions to take into account, maybe a character featured in a scene is dead at this point due to a prior player choice. Do you play a different scene, swap in a different character, or design the scene in a way that the character isn’t necessary to the conversation (Bruce Willis in The 6th Sense)