The (Current) Process of Character Asset Creation
By Akrid 7 Comments
'Sup! I spent most of my weekend trying my hand at a character's head in 3D. I think it turned out pretty well, so I thought "Why not share what I've learned with the internet?" and here I am. Full disclosure: I'm a hobbyist, been playing around in 3D for two years or so. This is my second and first time working with zBrush and topology respectively. I'm not a great artist, but I think I know my shit at the least. But of course I may be wrong, so vets feel free to call me out on anything you see that is erroneous.
I did this initial sketch in zBrush, a program that allows the user to sculpt polygons in much the same way as you would with clay. I was going for a krogan sort of guy, but looking at pictures of Wrex I guess I severely misremembered some things. Anyways, the problem with the sculpting method is that the resulting model has too many polygons, can't be animated, and is in general just very cumbersome to work with. So often in a studio the model is sent to another modeler who specializes in a technique called "Retopology". Probably the most often forgotten link in the chain, Retopology is an essential role that involves re-doing the entire model, using the original sculpt as a sort of three-dimensional reference. I figured I'd try it out for the first time on this model!
The tools and methods vary slightly from program to program, but with the one I use I place the hi-res mesh in a background layer and constrain the polygons I make to the surface of the hi-res. This allows me to get most of the spatial information I need instantaneously, making it much quicker then if I modeled the head from scratch. The whole idea is that the correct "Flow" of polygons will give the maximum amount of detail with the fewest amount of polygons. Unfortunately, there are many conflicting ideas about what constitutes good flow and the issue will never be cut and dry. Ultimately It's up to the individual to figure out their own style. I should probably explain that in 3D, a polygon with 4 sides is ideal. 3 (tris) and over 4 (n-gons) are less so. Also, a point with 5 or more sides are entirely neccessary but have to be handled very carefully.These are the main rules you have to adhere to when retopologizing.
So this is the wireframe render of my fully retopologized model. I managed to go from nearly 4 mil polys to 1,751 polys (No SDS, with: 20k or so). I think this would be suitable for game res, as I've heard that there are around 15,000 polys total in a current-gen character. This is my first try at this, so I lost a ton of detail that I had in the original hi-res model. i also got really sloppy at the back of the head there due to fatigue. There are many ways to add these detail back in using texture maps, but that's another subject entirely. Also, ideally I would have connected the face with the back of the head and make it one big continuous mesh ........ But......... No. Notice how I added the nose, diverging from the sculpt. The only reason was I had a lot of lines that needed to go somewhere, and a nose is a great place to hide things in. There are probably a few more ways to improve this model, but I'll look at it with fresh eyes later.
All this work took up the saturday afternoon sculpting (probably should have spent more time on that) and literally all of Sunday retopologizing. To put it in to perspective, I probably have about 1/15th of a fullblown character here. I'm sure a professional could go faster, but my point is, 3D design is not a solitary pursuit. At least, it isn't if you're attempting game/film quality. That said, I thoroughly enjoyed working on this guy. Retopologizing is fun, and surprisingly natural. it's like a big puzzle! Overall I'm pretty happy with how it turned out.
So... I guess I may be doing a 3D blog. If I end up making another, would you like it dumber/smarter, longer/shorter, funny/serious, polite/rude, adjective/antonym? Do you care about the nitty gritty details and explanations or do you just want me to post my progress? Is there anything that's still unclear? Does this sort of thing belong on GB? Would you enjoy reading another one? Please tell me all these things and more in the comments.
P.S, sorry about the lack of WIP images, this was sort of an afterthought.
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