NPC interaction will be a major part of my game so it's really important that the engine I'm using can do this.
I'm not great at explaining so I'll try painting a picture.
Basically take this screen from Undertale: https://vignette.wikia.nocookie.net/undertale/images/a/ac/Snowdinshopkeep.png/revision/latest?cb=20151030093324
A full-screen picture of the NPC(s) you're talking to so you can see their changing facial expression/posture. Instead of the black box at the bottom, there will be speech bubbles all over the screen. Different bubbles will do different things. Some will interrupt the NPC and talk over them (eg. Greeti... "Your barn is on fire!"). Some will be fleeing thoughts that fade away and you have to click on while it's on the screen or you'll lose the opportunity forever. Some will only pop up if you hover over a specific thing (eg. you hover over NPC's scar "How'd you get that scar.")
IT also needs to be able to keep track of time and your cursor's location and do stuff based on that. Eg. if you keep your cursor on an NPC's face and say nothing for 30 seconds they will be weirded out and comment on it.
Also for reference, check out Oxenfree's trailer for how the dialogue works there, I'm going for a similar effect.
I'm not great at explaining so I'll try painting a picture.
Basically take this screen from Undertale: https://vignette.wikia.nocookie.net/undertale/images/a/ac/Snowdinshopkeep.png/revision/latest?cb=20151030093324
A full-screen picture of the NPC(s) you're talking to so you can see their changing facial expression/posture. Instead of the black box at the bottom, there will be speech bubbles all over the screen. Different bubbles will do different things. Some will interrupt the NPC and talk over them (eg. Greeti... "Your barn is on fire!"). Some will be fleeing thoughts that fade away and you have to click on while it's on the screen or you'll lose the opportunity forever. Some will only pop up if you hover over a specific thing (eg. you hover over NPC's scar "How'd you get that scar.")
IT also needs to be able to keep track of time and your cursor's location and do stuff based on that. Eg. if you keep your cursor on an NPC's face and say nothing for 30 seconds they will be weirded out and comment on it.
Also for reference, check out Oxenfree's trailer for how the dialogue works there, I'm going for a similar effect.