>I was wondering how an idea (let's say of an enemy for a game) goes from
>drawing on paper to a moving character on screen. Please give me an e−mail
Usually, somebody draws a pencil sketch of lots characters and variations. When one is chosen to be considered good enough it is then re-drawn in color in detail. This is so that people can comment on colors, clothes design, things like that. After that an artist might make a 3D version of the character while at the same time a designer will figure out all the animations that will be needed for that character. One reason for the color drawing is if the artist that drew the color picture is not the same artist that's making the 3D version the color drawing makes it clear what they are supposed to make. If it's a main character there might be 50+ animations. For example I think Gex 1 had 57 animations. If it's a simple extra character it might be just one or two. The designer will usually try to sketch the animations by drawing a few almost stick figure sketches of what they want with some notes on the side for explanations. Once the animations have been specified and designed an animator (possibly the same artist as before) will create each of those animations.
Then, all of that information will be given to the programmer so they can "cook" the 3D files and textures and various information and put it into the game and the program it to use the correct animations at the appropriate time.