When I first started 3D modeling, I had big aspirations to create spectacular assets but found myself stuck at roadblocks quite often. To get answers, I depended on my classes in college, books or the internet, but often my projects fell short due to not having the proper information and later I paid the price in time because I would have to go back and redo things.
The truth is, in 3D there are so many obstacles and a lot of times issues come up on a specific project basis, but today, I'd like to share just a few tips that I wish I had known as a new 3D modeler and texture artist to help others save time hopefully.
3D model the whole asset or don't?
When 3D modeling a character or prop, you may be wondering, should I model the whole body or prop as one object or is it ok to 3D model it as separate objects? For example, let's say your character has a fantastic costume and you don't see but the hands and head of the character's skin, so, do you still need to 3D model everything underneath the suit? Well, the answer is not so black and white, but in my experience, in many cases, the answer is yes. However, knowing what will be happening to your 3D model in the end, will help answer this question a lot better. In a lot of cases, it is safer to model a full base mesh as opposed to not.
A more obvious reason is, depending on circumstances down the pipeline, you may find that some skin needs to show under the costume, this could be because perhaps there was an amendment to the story and it now calls for a rip in the shirt or maybe no shirt at all for a particular sequence.
Another reason that may not be as apparent is, though you can pose a character or asset just fine without a fully 3D modeled body underneath if you rig it in a program like Maya, that process is super time-consuming. So to save time you may opt to pose it quickly with a program like ZBrush, but you'll find it becomes challenging to use PoseMaster with Polygroups when there is no full-body mesh to form gestures with. If you choose to pose in ZBrush, it is a lot simpler to group assets with Polygroups, then hide everything but the base mesh and then pose that base mesh to get a flowing gesture. It's a heck of a lot easier once you have a single flowing base mesh to align the other assets with that form.
Combine geometry or leave them separate?
So now you have the scoop about base meshes, but what about smaller parts on the base mesh, like fingernails or maybe a belt and belt buckle, should they be 3D modeled as one piece of geometry or combined? I mean, should I combine the teeth and gums into one piece of geometry or not? Well, yes they can be combined, and in some cases, it's just fine to do so, however, if you plan on texturing, rigging, or rendering the asset, combining can indeed cause complications. A pretty safe way to avoid this would be to just 3D model all assets separately and combine similar objects that share the same material.
An example of what may cause trouble later in production would be when you are working with materials, and you assign two or more materials to a single piece of geometry.
The troubling part comes later when you need to select a particular material to adjust, because it may be very hard to impossible to choose the correct geometry since face selection is not always an easy method to control what you what you need. However, in Maya, you can select a material on an object by right-clicking the shader in the Hypershade, but it's a lot more work to do that compared to just using the cursor to select the object in the Viewport. Something else to think about is if you plan on having displacement or normal maps they may not show up when combined with another material when you render. Also in certain instances, I've experienced when you combine two objects into one, that, even though you can double-click to choose the whole object with that specific material in a combined group, that, sometimes when rendering only one material shows up due to a bug.
Finally, if you rig your character or prop and later find out that you needed to adjust one part of the combined group of objects, your vertices will not be the same once you separate them. Separating objects can cause all kinds of issues when rigging or using blendshapes. The simplest way to dodge all of these potential catastrophes is to combine objects that share the same materials and for assets that seem like they should be combined but have a different material just put them all in a group.
UV map as you model or UV later?
The question of when to UV map your 3D model may seem a bit strange to some but is it indeed that important to UV as you model or should you just 3D model everything and then UV map at the end?
Again, and like many situations in life, it's not so cut and dry of an answer but in my opinion, doing UV work as you are 3D modeling is a great approach and can be time-saving in the long run. I think the most practical reason for why you'd want to UV map while 3D modeling would be to reuse parts to save time. For example, maybe you have ten pillars in a cool environment you are making, and they are all the same design, sure you can duplicate them but doesn't it make more sense to UV map one of the pillars first and then duplicate that one?
On top of UV mapping assets that are the same design, as pointed out in our pillars example, you may want to instance the pillars. Until you are entirely sure that you have a right look for the digital set, UV mapping and instancing a single pillar gives excellent control over the scene, that way you can adjust just the one, and all the other pillars receive the same changes, what a benefit! Keep in mind that UV mapping and instancing while you are 3D modeling doesn't have to be just about hard surface objects, organic objects, like teeth, fingernails, eyes or you name it, reap the rewards of time-saving with this method.
Conclusion
So there you have it, just a few tips that hopefully will help save time so you can 3D model with no hiccups, right? Just keep in mind that there are so many more reasons not mentioned of why specific methods make a procedure better or worse than not, but I've only listed some; however, these few should get you in the right direction to start!