Retopology is like eating ice cream: you first have to eat the biscuit cone to get to the good part. Why not buy it in a cup you say? Because then this analogy would fall apart. I’m simply trying to make this more interesting. Just go along with it.
Proper topology is necessary for detailed sculpting, animation and optimising a model for games. For beginning 3D artists, retopology can be a drag, especially if you don’t know what you’re doing. There are a lot of great tutorials out there on the interweb, but I haven’t yet spotted any easy-to-follow tutorials on retopologising hands. So, in this blogpost I’ll share a simple method that works for modelling and animation, while outlining the basic principles of retopology.
First, a quick run through the basics. The white lines in the two shapes below represent the edges of polygons. Usually 4 polygons will share one point, which makes their edges form a cross shape. This is what you want on most areas of your model. However, sometimes we need five polygons to share a point, which makes their edges form a star shape. This is called a pole and is typically used to redirect polyloops. Poles can sometimes cause issues in animation because they don’t deform well, so we have to be careful not to put them in areas that will move around a lot.
Below is an overview of how we’ll place our topology. We’ll start with a loop around the wrist containing 18 polygons, 9 at the front and 9 at the back of the hand. Make sure there’s an even amount on both the left and right sides.
The only poles needed for this method are around the thumb, where we’ll place 4. These are outlined in red in the pictures below. We’ll place the first two at either side of the thumb, with one edge connecting the two poles. Then we’ll do the same above the thumb, making sure to keep it symmetrical. Proceed to loop the polygons around the thumb. There should be 6 faces around the loop of each finger. Extrude the edges of this loop until you get to the tip, where you'll close it by placing two polygons.
Repeat this process for each finger and, voilà, your character is ready for further sculpting or animation!
Or retopology of the rest of the body. You’ll get to the ice cream eventually.
Pia Stene Wichstad
Lead Character Artist