Base Models

One of the major advantages of 3d modeling over traditional sculpting is the ability to produce a base model or component. This base model can be used to rapidly design alternate versions, accessories, and even different models that use the same dimensions or snap-together parts.

By making effective base models, you can greatly decrease redundancy and wasted time during production. Those who are familiar with video game design also know that it allows for the same rigging to be used for multiple models. I find it interesting that rigging seems to be absent from 3d miniature design, but more on that later.

So, what are base models and how can they be designed effectively?

Lets tackle the first question. A base model is simply a boiled down and very basic version of the final product. It has no outstanding details, but should convey a general feeling of what it is, be it a car, gun, human, house, etc. Remember that it still needs to have defining features, just not specific to an individual model.

Here is an example:



This is obviously a human male, but it doesn't contain any specific features. This could potentially be anyone.

Now how do we make effective base models? Remember, a base model is meant to save you time and reduce your work load. This means that you will need to focus on two points:

A) How will this model be used in the future? (basic geometry)
B) What features will be common among all the models? (details)

Question A is for the basic geometry. Say you're making an assault rifle, as an example. You might say that all rifles have a grip, a trigger, a charging handle, a barrel, and a magazine. So basic geometry should reflect all of these, right? Not quite. This is where you must evaluate your future designs that will be based on this model. If you are going to make a bullpup configuration, a conventional magazine well would then need to be moved:



In the above image, we see two rifles. The top rifle is a bullpup with its magazine behind the grip. The bottom is a conventional rifle with the magazine in front of the grip. Those of you who don't study firearms might be thinking "So what, just move the box back and call it good!" That's great if you're making low poly models for an RTS, but people want more detail in their miniatures.

If you move the magazine back, you also have to move bolt, and ejection port back, increase the size of the stock, and change the hand guard. Generally you'll need to shorten the barrel as well. So now you're doing a lot of work to retool a base model to fit the same item type. This is also true for organic models, cars, airplanes and everything else. You don't try to make an F15 fighter out of a cargo or biplane base.

So, you'll need to consider what you're finished product will be. Are you going to make 30 or 40 assault rifle variations? Get pictures of each weapon and sort them into groups by common features. A quick breakdown can give us:

Handguns

Semi-Automatic

Revolver

Assault Rifle

Standard

Bullpup

Rifles

Bolt Action

Automatic

So you see how this can break down into a lot of base models! This isn't necessarily a bad thing if you have a full art team, as some people will be making base models while others add detailing and finalize them. It can be a bit much for one person though, so it's a good idea to prioritize your models. Use just a single type until you've completed your goal, then branch out as you have time. Using the assault rifle example, you should pick only a couple types of weapons to begin with, such as semi-automatic pistol, standard assault rifle, and pump action shotgun. This gives you three base models to work with and keeps the scope of your project much more reasonable.

Once you've narrowed down your base models and their basic geometry, you can move on to the second point. Given a single base model, what will all of the final models have in common? It is important to compare each model and determine what similarities there will be between them. For example, all of your semi-automatic handguns may have recoil operated slides and round trigger guards. This is a detail specific to automatic pistols, but not other weapons.

For example:



You'll notice that, despite color, size, and model, each one of these handguns have striking similarities, especially when contrasted with revolvers. So the question is, why redesign the slide for each weapon? For miniature games (especially 15mm) these details need not be very specific or varied. You can replicate these subtle details over many weapons without the design becoming boring.

Consider the following example:



This is the base model I made of a Warhammer 40,000 bolter. I knew that if I made any alterations, they would not be with the charging handle, magazine well or grip (actually, its a specifically designed flat area, as space marine hands have the weapon grip molded into them. You just have to make certain to design the weapon to properly fit over the hand). I decided to extend out the barrel and add an integrated, bottom fed grenade launcher.



Notice how I was able to simply extend the front and model the grenade launcher? I didn't need to change any of the subtle details (though I did decide to take off the front sight aperture, as I felt it was redundant with a holographic sight). I then decided to completely break away from this concept. Using the same base model, I shortened the barrel length and added option "lock in" parts:



95% of the details on the bolter remained the same, with only a minor reconfiguration of the foregrip and bottom mount for combi-weapons.

Now, obviously you can decide to get crazy with your designs and make everything completely unique. It might even sound very good on paper. However, I have to advise against this. You're severely limiting your output and variety of models, plus you're reinventing the wheel with each model. Even if you don't specifically intend to produce multiple models or kits, making a base model can allow you to revisit designs or start over if you don't like the end result.

Even more important, if your clients like the work and want derivatives, you don't have to start over or dramatically alter the finished product. You'll have a large portion of the work already completed. You can then offer a discount on the work, or seriously cash in on an easy project (though you'll get more return work going the discount route).

As always, I hope this helps an thanks for reading!

The Importance of being Hollow

Let me start this with a bit of random trivia. A viagra knock-off company in India has generated 9 hits on my blog this week. Maybe they enjoy 3d modeling?

Anywho, as the title says, it's very important to be hollow. At least if you're a 3d model. See, all 3d printing companies charge per cubic centimeter of material that your model contains. This means that models can start to cost a lot of money. How much? Frosted Detail (FD) runs $2.39 US per cubic centimeter. If you wanted a high quality 16mm die, that would be 1.6cm^3 * $2.39 or $15.66 per die! Yikes!

To decrease this cost, we hollow out our objects so that they use less material. Generally this does not effect the component, since it's either too small to be effected, or meant for a prototype and will never be used.

*SAGE ADVICE* If you are planning on creating masters for mold making, you will want to be -VERY- wary of hollowing your models. Many mold making processes involve a lot of pressure and heat, and will result in a broken master and ruin mold if the model is too weak. Generally speaking, I advise anyone who plans on 3d printing masters to either use wax for bronze casting or make certain that your prints will be very solid, even if they do cost much more.

Alright, so lets look at the quick and dirty method of hollowing out an object. First open up the object you want to hollow out. In my case, it is a very fancy looking box magazine.

An important thing to keep in mind is structural integrity, both as a requirement for printing and for functionality. In the case of my magazine, it is going to be printed in Frosted Ultra Detail (FUD), which has a minimum wall thickness of .5mm (half a millimeter). In addition, it is meant as an accessory to a machine gun, so it must be able to lock into the machine gun's magazine well without breaking. This means I have to be careful about the guides I design to fit it in place:



First I'm going to copy the magazine by selecting the Move tool (or M) and pushing the ctrl key once:



Because I don't want to weaken the magazine guides, I'm going to remove them from the copy:



Now that it's cleaned up, I can scale it down, say, 15% using the Scale tool. To scale it exactly 15%, use the scale tool as normal, but type .85 in for the scale amount. If your remember math class from all those years ago, it means you are reducing a number TO 15% of it's original (or reducing it by 15%):



Now for the tricky part. we need to move the smaller magazine so that it is in the exact center of the original. We can do this by creating some center guides. But keep in mind that the smaller version won't light up exactly with the larger one, but we can still find a good fit by using the guides:



Now, hide part of the large magazine by selecting half of it, right clicking, and selecting Hide from the option menu. This will allow us to move the smaller magazine into place:



Remember your minimum material thickness, and measure to be certain. If you believe some areas may be too thin, just scale down the model by 5%. Once everything looks good, select the entire model, right click on it, and select Reverse Faces from the menu. This will make the distinction between the inner and outer walls:



Almost there!

Now Select both models by drag selecting. Right click them and select Explode from the option menu. This will break both of them out of the component state, and allow them to be recombined as a single model:



And that is the cheap and easy way to hollow out a model. You can actually hollow very complex models in a similar way. However, not all models can be hollowed using this method, but I'll cover that in another blog post.

Until then, thanks for reading!

First Post

Ah, so here we go, a blog. Where to begin? Maybe I should start with my intentions.

Keep in mind, I am not an artist, not in the least sense of the word. I make horrible stick figures and scraped by my high school drawing class with a D+. But, I was rather taken recently by the prospect of 3d modelling. Interestingly enough, 3d modelling is not a normal medium like oil or charcoal. No, it is its own, unique form of art.

Those of you interested in it might rejoice in the fact that it does not require great artistic talent to master. At least, not that I have seen so far.

Also let it be known that I have taken no classes or made any studies in the field of 3d art or animation. Everything in this blog will be from my own trial and error, and perhaps, a way for you to avoid the same pitfalls. I do not assume to be a master, expert, or even journeyman in such things. But maybe that is for the better. There are more students than teachers, and there is something to be said for group learning.

As a brief history: I started playing with Google Sketchup (v8) in mid-December. My objective - to design a 6mm scale tank (roughly the size of a quarter)for 3d printing by a company called Shapeways. After a few hours of trial and error, I had something that looked like a tank:



I promptly uploaded it to Shapeways, where their automated system promptly laughed me off the internet. See, it's not enough to simply make a 3d model. Printers are very expectant machines. They expect to know where to begin and where to stop. What is on the outside, and what is on the inside. Where one object begins and another ends.

Being only vaguely aware of such things, I started googling anything and everything I could about 3d printing. Finally, I figured out exactly how the model should be put together. But I didn't feel like continuing on my tank yet. I felt I needed to start smaller, with a basic structure that already exists.

So, I started playing with a bolter from Warhammer 40k (a 28mm scale strategy game). I decided I needed to do 2 things. The first, was make a base model to drive all others from. This would have the same dimensions as a normal bolter,so I could add or remove additional features without worrying if the bolter would fit the model it was meant to go with (Space Marines):



Bummer. With that in mind, I decided on
With my base model completed, I decided to make a larger, more "assault rifle" version. I increased overall size by around 40% and and removed the front sight aperture in favor of the holographic sight. I also decided to incorporate combi-weapons, the 40k equivalent of under mounted weapons:



The problem? Well, it was too big:



Bummer. So it was back to the drawing board. I decided that I would decrease the size so it was only about 20% larger, and add modular optics, combi-weapons, and magazines. This way there would be much more customization:



It looked better, but there are still size problems. I'll introduce those in my next post.

The second thing I realized I needed to do, was begin making a component library. In Sketchup, a component is an object or objects that are generally considered finished. You can copy components out of the library and right into the workspace. In this way, I could make a base scope mount. Every time I make a new scope, I just copy the mount in and start working, then save the new scope as a different component.

Because I can very rapidly build from a base model or interlocking component, I'm able to add much more variety to my models than would be possible through conventional modelling. At least, in the span of time it takes me.

The downside is that any changes to the base model will require changes to the components. For example, if the top of the bolter were to become wider, the scope mount would have to be changed to match.

Making modular systems requires a lot of pre-planning so you don't end up doing the same work several times, something I've been learning the hard way and will share in a future blog entry (you're going to notice a pattern here).

So, stay tuned. I have some interesting things planned for the future.