Retopology.

Retopology means modifying the topology of a mesh; in simple words it is placing faces on our model again. It is useful for animating purposes as it reduces the resolution of the object. During our classes we have learnt different  ways of retopologizing geometry in Maya. When the mesh is too dense in faces, or faces are not quads, it can mess up the animation process. Therefore, it is recommended to, especially after we have added extra divisions to our model to work on some facial details, to remesh our model.  

As mentioned, it can be done in several ways. The first one is to simply click on a Remesh option and Maya will automatically adjust the faces to the numbers we indicated in the option box. This method is certainly the quickest, but not the best one as in the end faces can have some odd shapes, or be placed in a strange way.

The best way is to draw quads, so to place faces over our geometry. This method creates a layer attached to our polygon and to do that we need to make our model a live target (magnet icon). Next, we draw quads and decide on the size and the layout we need. 

This is a time-consuming way, especially if, like me, you do not have any prior experience of quad drawing; at the same time, it is much quicker than re-modelling a character (which I did many, many times).  

After the process is completed, we should achieve a clean mesh built out of quads (4 vertices, and 4 sides face, necessary for animation work in Maya).

I practiced quad drawing during one of our lectures, and later, on my own character in Maya. I, however, have not finished it, so will not be using the retopologized low poly model in the project I am currently working on.