When I read any book, I generally have a scene in my mind. I've always done that. Even when I'm reading a history book or something I'll have a scene in my mind, unless it's something like "The XXX war was in year XXX." If I read something like "The soldiers fought the British in their bare feet, having eaten their shoes to sate their hunger during the winter in Valley Forge," then I'll instantly imagine some half dead soldiers fighting British soldiers without shoes, complete with muskets and bayonets and everything except voices. The voices are both distinct and indistinct at the same time, if that makes any sense (I haven't thought about that part much) Other than that, though, I can visualize pretty well. It's not normally a moving scene unless it's from a video or I specifically think about it in a moving way, though. Apparently not everyone visualizes stuff like i do, though. I remember my 8th grade social studies teacher asking my class if we visualized what we read, and I guess most of the class didn't.
The weird thing is that if I saw people in real life like in hentai (or manga in general), I'd probably be extremely creeped out. It's fine if I visualize a hentai or manga, but if it were it real life it wouldn't be the same. It's kind of like doublethink, I guess.