3D I – Facial scanning and polygonal reconstruction
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This week (really a few weeks ago, I’m late with this), we had the opportunity to do something rather nifty. Everyone that wanted, could have their own face photographed, to later use these images and create a 3D scan of it! Me, not being one to turn down a new experience in the 3D field, was very interested in this! We all went to the MoCap-studio here on the island (which really was just next door from where we were), had dots drawn in various places on our faces, and then had a sit-down on a chair in the studio itself. Here we were photographed from a multitude of different angles. However uncomfortable this is, here are a few of these photographs:
See how happy I look? Once I acquired these photos, I imported them into a software called Autodesk 123D Catch. The first time, it generates a mesh as well as it can. It scans through the photos, trying to find good points to track and, using these, determine their 3-dimensional position and from that the shape of the mesh. This. Was. A. Mess! What I got from this didn’t even resemble my (or anyone else’s) face at all. Due to this, I had to go in and manually point out what to track, and help it along the way. I probably added over 15 new points before I got an acceptable result. I feared, that if I were to continue, it would break somewhere and get even worse. It was by no means perfect, but served as a good enough base to start the retopology on.
Retopology Bringing the generated face mesh into 3D Coat, I started to map out the topology. As explained in a previous post, some people like to make heads/faces starting from a cube. It also explained that I do not! What I like to do is, to start by creating an edge loop around the eye, and another around the mouth (just at the outer edge of the lips). This serves as a good starting point, and will ensure that I maintain the edge flows in these key areas. These are the ones that move and emote the most, so this is very important. From here I usually keep extruding from these circles until they nearly cross. This also leaves a “hole” for where the nose should be.
Once the basic edge flow is defined, I start to connect these areas. I start by extruding the eye area towards the nose, creating a sort of super hero mask. From there I extrude downwards toward to the tip of the nose. At this point there is a gap between the key areas where the cheekbone would go. To fill this in, I work from the nose, just above the nostril, and move outwards, connecting the eye and mouth loops as I go. Eventually, I get to a point where directly connecting these areas just doesn’t make sense anymore (just where the long “horizontal” arrow stops). Here I create what’s known as a “star”, where multiple edge loops come together. This is pretty much the end if the “face” itself, and from there on out the rest is part of the head and skull.
Once I was done with the retopology in 3d Coat, I brought the mesh into Maya, where I continued to tweak it. This part I did completely manually, basing my decisions on the reference photos that were taken earlier. This is the finalized face:
So there you go, now you know what my face would look like if it was completely grey and was detached from the rest of my body! OuO |
Too ease up the process of modeling a face that would be able to emote a variety of different facial expressions, we had to keep our face as neutral as possible throughout this process.
