Transition from 2D to 3D

[topolinik]

WARNING: this is not a feature request, not a suggestion for developers, no work intended here, not a proposal for residualvm roadmap modifications.
This topic is just a geekish imaginative free wild ride. If this is not your intended contribution, then avoid posting your comment. So...

Hello, I have read this article (it's an italian IT magazine) and I though "it would be great to have a 3D Monkey Island! It should be a First Person... Adventure Game, a game in which I can freely move and interact with any object. But... it sure requires a lot of work!"
Do Doom/Quake engines (or their evolutions) support interaction with other characters, aside from shooting each other? I actually don't know.
Now, ResidualVM gives wide portability of 3D capabilities, so I think it would be a good choice for this developing.
But "The secret of Monkey Island" is a 2D game, and it requires ScummVM, not ResidualVM. Well, actually ScummVM has developed a script interpreter which could be useful, because if I want a 3D Monkey Island, it has to be Monkey Island, so it should be based on its own original script. This script defines locations, actions, object interaction and character interaction. Well, here's the first question: is it possible "importing" a game script reader from ScummVM into ResidualVM?
Perhaps this script loads some bitmap that could be used as a texture but no 3D model of any object. So... this project needs every object to be created. Ok, this raises the second question: is there a tool for creating 3D objects for ResidualVM? (is a GrimE tool as good in any way?)
And further, what about moving? I remember into an adventure game, locations are identified by a "room" number, so when the main character crosses a given line, then the engine loads a different room/view. Well, in a 3D game I won't have room/view changes because it will be myself moving into a 3D world, and it has to be fully created form the beginning (or every location change may be masked by a fast fading when the character walks through a door, ala Silent Hill), resulting in high memory/cpu requirements.
Things are rapidly becoming quite complex... Not to mention the needed rework of music, sound effects and high-res textures.
How do you evaluate the actual feasibility of the whole thing?

[bgK]

To make the answer short, a full 3D game and a 2D game from the early ninties are such different beasts it'd be simpler to start over and rebuild the game from scratch than hoping to recover anything.