This week I started on the retopology of my head model. I’m a whole week behind because of work commitments and a busy weekend. So I’ve taken Sunday to catch up 1 week. The plan is to make time at work for the 3rd week and get 2 blog post done by Friday.
I haven’t had much practice at this in the past. It’s something that is done by the character artist before delivery to the Animation department. It’s usually a two way process until the edge flow is indicative to good deformation. The general rules for retopology are:
- Nice edge loops that follow the muscle structure.
- Try to get a nasolabial fold that flows around the jaw and over the nose
- Keep the inner eye loops radial as well as the inner mouth loops
- Try to maintain the same number of divisions above and below the top eyelid as the bottom eyelid
- Try to maintain the same divisions on the top of mouth to the lower mouth.
- Try to keep an even distribution of polygons in the facial area.
- Keep those nasty stars out of animated areas
Obviously character design will dictate some of the major loops in the face, they just have to be there to hold the form of the character. But what looks good in a still pose, doesn’t always hold true when it moves.
At first I used Maya retopology tools that are bundled into the modelling toolkit. They are quite good and easy enough to get going. I did have to mess about with the shaders to get a nice readable surface to work with. I found the edge extend methods were the best way to me to block down the loops. Either extending a single edge or a complete loop. The smooth tool was also very good and essential to getting a decent polygon spacing.
Once I’d fleshed out the entire head minus the ear, I brought in the ear from the Zbrush obj export. I quickly reduced the ear with Maya reduction tools then massaged the loops to match the vertices I had in the ear space on the head. It wasn’t tricky, but I did think that time permitting I would have liked to model a better ear for this character. Ears won’t be essential to his personality so I think I’ll get away with it.
Once the ear was stitched into the model, I moved onto good old fashioned poly modelling. The tweak mode in Maya is really good for this and has improved a lot over the last few years. So much so I didn’t want to move to Modo or Softimage for this stage. The introduction of Mudbox sculpting into Maya was a missive help as well. It just worked. I only wish it worked with a “live surface” so I could slide the points around. While doing this I was occasionally rendering the character to asset the final look. It’s important in the refinement stage to keep an eye out for any unforeseen issues. While I’m talking about rendering, I’ll also mention my camera settings. In traditional photography you’d take a portrait photo with a 80mm or 100mm lens. It stops the proportions of the face from becoming distorted. I set up my camera while modelling to a 100mm focal length in Maya. It makes all the difference and really helps me with form, shape and silhouette.
The final phase was the mouth sock. I generally model characters with a closed mouth. So I used the sculpting tools to ease open the mouth. I experimented with skinning the jaw to open the mouth to give me room to model the inside. It was working well but then Maya crashed! That set me back to before the opening of the jaw. For round two I just extended the edges to form the inside of the mouth. It’s tedious and something you wouldn’t do time and again in production. You’d start from a base mesh that you’d form into your new character. However this is for self growth and all that jazz, so a little pain is required for your art.
The next step is to build the teeth. Well time was well and truly running out so I brought in the teeth from the model provided on the course. I think it’s important to get the correct placement within the mouth. Making sure the lips rest naturally on the teeth and gums.
Finally I quickly wanted to get some hair onto the character. A quick sculpt and I got this. It needs work but I want to try XGen rather than poly hair. So this is just a placeholder.