Introduction / Concept
Soon after the Dominance War 2 competition ended over at Gameartians.org, a new competition started sponsored by Big Huge Games. The subject was to create a creature of epic proportions, something that would tower over the player in a game. I had so much fun creating Thrull, I really wanted to take part in this new challenge. I knew i wanted to create a monster but also wanted to create something different than my last character...otherwise it wouldn't be interesting.
So, I took out the sketchbook and started scribbling down some ideas. Eventually I came up with Leviathan, a giant creature that resides in the water and coastal areas. I'm not the best concept artist in the world by any means, but
it's always a good idea to have at least a rough sketch to get your ideas down and make sure everything will work.
Note : The small human model was provided to me by Big Huge Games.
Base Mesh Modeling
The fun begins. The first stage in character modeling for me is to create a base mesh that will be used as the foundation of my high poly sculpt and, once it's reduced and cleaned up, my low polygon model that will be used as an in game asset. The main thing to keep in mind for this model is to have nice, even polygon density throughout your entire mesh. This results in good subdivisions once the model is brought into ZBrush and will cause you a lot less headaches in the future. So, even though the forearm on your character wouldn't normally have a few edgeloops on it, add them for the sake of sculpting...they're easy to remove once the time comes and the benefit will show itself in the results of your high poly sculpt.
You'll also want to avoid complicate geometry that would normally be acceptable in a game model but not neccessarily in a mesh for sculpting in ZBrush. By this I mean avoid triangles and terminating edges in awkward places. Try to keep your mesh in all quads. Don't worry so much about adding definition to your model as a lot of it can be sculpted in ZBrush. Sometimes I will add geometry for things like kness or elbows but more often than not I avoid it as the effort spent on creating them usually isn't worth the trouble, especially considering how quick it is to sculpt in ZBrush. Just worry about the major forms of your model and how it will react to subdivisions in ZBrush. It's tough to say what your base mesh model's polycount will be as it really is a case by case basis. Leviathan's base mesh polycount was around 5000 quads.
The method I use to model is commonly referred to as edge extrusion modeling. Basically, I start with a cube, delete all of the faces but the one facing forward on the Y axis. I split that in half and instance it, mirroring it on the X axis. From there I grab an edge and start modeling out the forms. A lot of people will disagree that this isn't the method to use as other methods, such as box modeling, allow you to block out forms quicker. But, with enough practice you can become quick with the edge extrusion method, most workflows now for game art doesn't require you to model a high density mesh (so modeling is generally quicker anyways), tweaking proportions afterwards is easy because of the base meshes low density and you get a lot of control over edge flow with this method. That being said, different methods work for different people...I just happent to like this one.
I use this method throughout my entire model until I end up with a full model that I feel will work well for my sculpting base. Keeping the basic shapes of muscle groups and bones in mind, how the model will deform once it's reduced to it's low poly form and most importantly how it will hold up in ZBrush ones I started sculpting away. I divide up the model into seperate pieces so that ZBrush will be able to subdivide them to the level that I want. You can see where I split the mesh based on the colour differences in the example below.
After splitting the model into different pieces, I export them as OBJ files. I open up ZBrush and import the object that I want to start sculpting, usually the first part is the head. I used ZBrush 2 for this character as ZBrush 3 wasn't available at the time.
Because characters are a case by case thing, I can't really say how far to take your own project. It all depends on
how much time you have, the style you're going for, map size, etc. If you have a large normal map allowance (such
as 2048x2048), getting into the finer details may not be a bad idea. If your time is limited you have have to just focus on the bigger forms and leave the finer details for Photoshop.
My workflow is pretty straightforward. I block out the detail that I want and then up the levels of subdivision as needed to add finer detail. Using the head as an example, I roughed out bigger shapes like the brow, lips, bones around the sye and side of the head and the ribbed skin on the neck. After that I just kept refining the shapes, tightening it up and making sure that it wasn't too blobby. Towards the end I added finer details that I thought would translate very well in the normal map such as the marks on the lips, divots in the skin and scars.
You can see how far I decided to take the indivdual pieces here:
Once I called the objects finished, I went to their lowest subdivision level and exported the tool as an OBJ. If no drastic changes happened to the mesh, I ignored this step but it's always a good habit to make sure your low poly model will match as close as possible to the high poly mesh.