How do I go about creating a model for my work? I'm glad you asked! Let me show you the basic steps to making one of my creations. Specifically, we're going to take a look at the process of making a goblin.
So, first we start off with a base model. Cause reinventing the wheel sucks and nobody wants to start from scratch every time they begin something. So I have a couple of different starter pieces with good basic topology that I can work from. If I don't have one that is suitable around, I'll frequently create a new one. This one is my halfling base. Since we want a scrawny character, this'll be the best initial starting ground.
Next it is time to add in details, starting off with all the symmetrical aspects, such as eyes, ears, fingers, arms, legs, etc. For pieces on the central torso, it is best to work with the full model, as that will give you a better sense of the shape. For things such as the arms and legs, it is possible to get away with only working on a single side, then mirroring the changes over to the opposite side. However, all of these alterations must be done before adding in any sort of asymmetrical detail, such as what I have done with the pant legs. Simple billboards are added in for details such as teeth to keep the poly count down. For this particular model, I have chosen to go for a very cartoonish effect. By enlarging the muscles of the forearms and calves in comparison to the biceps and thighs respectively, it gives him a more stylized form. But most importantly, for any sort of animated character, it is critical to maintain good topology from the base model. Otherwise, there will be weird distortions around the joints and the model will not move well.
Now, it is time to add in seams. Seams are the way in which a 3-d model gets prepared for 2-d texturing. To do this, I need to determine where seams are going to need to be in order to make this unwrap cleanly. Generally, anywhere that has a very sharp difference in texturing (such as where the pants are) or where there is a sharp change in the topology (such as the base of the extrusion that joins the arms to the chest) is a good place to put a seam. Additionally, seams need to go anywhere you have a cylindrical shape, along one side of the cylinder, so that it will lay flat. Usually, I put these as out of sight as possible. During texturing, it will be especially important to make these areas match up smoothly so that seam lines aren't visible. However, it helps if they are on the interior side of the thigh, where no one will be paying much attention anyway.
Time to unwrap the model! It is critically important to make sure that the model gets unwrapped appropriately, as if it is done inappropriately it will be impossible to texture correctly. From here, it is possible to arrange the pieces on what will eventually be the texture for the character. Avoid having pieces overlap (unless they are mirrors of each other, in which case it is fine as long as they match up exactly). It is desirable to cover as much of this space as possible, so you can get more detail work on the model. Generally, you want pieces to be laid evenly, so that the whole model is at the same resolution. However, higher detail areas, such as the face might require more space, depending on what you want to do with the texture. Once this has been laid out to satisfaction, it is time to start texturing.
Texturing gets done in a variety of ways. Usually, this involves some mixture of working in the modeling software and bringing the texture out to some image editing software such as Photoshop or GIMP. My process involves exporting my UV layout, adding a basic coat of color in the modeling software, then taking these out to GIMP to add in details. I'll then periodically re-import this into my modeling software to see how it looks on the model itself. Once outside texturing gets finished, I will bring it back into the modeling software and clean up any bad seam lines.
Aw man. The actual modeling process is finished now. So let's get this sucker rigged up. We start with creating a root bone. Every other bone in the skeletal structure is going to trace back to this bone, and it is highly important that this remain at (0,0,0) on the coordinate grid. Also, mark it as a non-deforming bone, as we don't want any of the skin connected to this bone. Next, for most rigs, you create a hip bone. Place this near the center of the character, moving from the groin up to around the waistline. Extrude the bone up from the ribs, chest, neck, and head. If you have a model that will have a lot of back or chest motion, you may wish to include additional sections. But for most humanoid models, this will be enough. Next, add on arms and legs. Parent these to the chest and hips respectively, then extrude them along their limbs. Also, remember that it is only necessary to work along one side for the limbs, as you can mirror bone structure across an axis, just as you could for the model itself. Add in any additional bones necessary from here. For the goblin, I wanted to make sure that the ears could wiggle and the mouth could move. Now, make sure to align all of these with the limbs and structure of the model.
Next, it's necessary to add in non-deforming bones for our IK constraints. These are what are going to make sure that our humanoid model moves like an actual person, simulating the constraints of the joints in the arms and legs. To set these up, we extrude bones out from the wrists, elbows, knees, and ankles in the direction the joint is constrained in. As an example, for knees this would be in the forward direction. Parent all of these to the root bone itself. Now, we set up the constraints. For the outer IK's, we want to give them a chain length of two, while the interior ones have chain length of one. This is what determines how far up the bone structure the effect of the constraint will propagate. We then link the IK's to the appropriate bone, usually the bone leading to the joint. So for the wrist, this would be the forearm. Once this is done, congrats. You now have an appropriately constrained human skeleton. Now we need to attach the skin to it, so we can animate this little guy.
The vast majority of modeling software will have an option to automatically attach your mesh to your skeletal structure. And this is usually a very good starting point for most meshes. However, the process is not perfect...so often times it will be necessary to clean up the weight painting of the model yourself. First, experiment with each of the joints. See which joints are moving what. Also, see what vertices on the mesh aren't moving at all. It is important to make sure that each vertex is assigned to the appropriate bone or some very strange things will happen when you go to animate the model. For organic structures, such as the goblin, you want the weighting to gently transition from bone to bone, such as with the shoulder. When moving the arm, you want a gentle stretching across the chest, similar to what would happen with actual muscle tissue. For inorganic structures, you will usually want a sharp cutoff between sections with no overlap. Many weight painters will export the weight maps out to image manipulation programs such as Photoshop. I will do this on occasion if I require the transitions between bones to be particularly smooth. However, doing it in the modeling program gives real time feedback, which is invaluable when trying to get these right.
Finally time to animate the model. We're going to set this up this one with a keyframe animation. What this does is set particular points in time for the model's rotation, scale, and translation. It will then interpolate between these points to create the animation. Firstly, we want to create a basic walk cycle for him. To do this, we need to start him out mid stride. As he lifts his foot up, we want to shift his weight over onto his other foot, which should be slightly bent. The leg he is putting weight onto should straighten, while his other leg fully bends. In the meantime, he should be sliding slightly backwards, so that the model itself remains in place. Now the bent leg moves forward and he slides forward slightly to put his weight on it. This process then repeats itself for the other leg and tada. You have a basic bipedal walk cycle. It is frequently useful to consult a guide online if you have trouble getting this looking quite right. Additionally, quadruped or octopod walk cycles are different, so be sure to consult a guide.
Congrats! This is now a fully created model. For some game engines, you will need to figure out the appropriate way to export this, but for some such as Unity, it is as simple as dragging and dropping the model in. To see the model in action, I suggest taking a look at my model viewer. You can find it: