Join Craig Barr for an in-depth discussion in this video Units and scale for UE4, part of Unreal: Architectural & Industrial Visualization.
- [Instructor] One of the most important aspects for creating a believable visualization is working with scale. Being able to configure your scale is very important for working within Unreal Engine. We're going to take a look at how scaling works and how to configure your scaling regardless of the 3D package that you're using to create your assets. What we want to take a look at is how we can work with units and scale. Most 3D applications work with the basic principle that one X, whatever that may be, equals one unit.
This holds true in just about any 3D package that you'll work with. Unreal works in the same way. What I mean by that is that, one, whatever you're working with can be your unit. Unreal, for example, likes to work with centimeters and I'd strongly recommend you set your packages to centimeters to be able to build real world scale. Now in this case here, so one X equaling one unit in Maya, one centimeter would equal one unit, or vice versa, one unit in Maya being one centimeter.
This allows us to define this within Maya and therefore match it to Unreal. I'm mentioning Maya because I'm going to use that. I'm going to use Maya to show how to calibrate the scale, but everything I'm doing in there is not Maya-specific by any means. It can be done in any package. It's just demonstrating how we want to calibrate that scale with our content creation package. With this idea of whatever being a unit, one centimeter equaling one unit, and of course one meter equaling 100 units, 100 centimeters to a meter.
Then of course, one kilometer being 100,000 units. Now let's flip over to Maya here and take a look at an example of how we can calibrate scale. Again, I'm using Maya. Any package that you use, this would be the same principle applying in here. I have this chair that I've constructed and built for our project. I have it in here simply just to show that we're working with real world scale, and I know that I am because I've built this asset to real world scale configurations.
However, by default, the Maya Viewport makes this chair look just visually like it's massive simply because the default grid is quite small in the center here. Here's how we want to calibrate our settings when we're working with any kind of digital content creation package to work properly with Unreal. First thing we're going to do is you're going to want to find in your package where you can find and define the units of measure you're working with. In my case in Maya, I'm going to go to my Settings & Preferences, Preferences.
Then I'm going to bring up that window and just click on Settings. By default, I can see that I'm working in centimeters as my unit. That's fine, I'll just cancel out of that. Now we want to go to configuring our grid because our grid is going to work like a ruler as we're working and it's going to provide not only a visual scale but something that we can lock our assets to for accuracy. So, let's take a look at how we can configure that. A couple of ways to do that in Maya, and of course any package you use, it's going to be a couple different ways.
To access the grid settings, you can go to Display, Grid. Or you can come over here and right-click on the little grid icon and hit Grid Options. That exist in Maya at the top of the Viewport. By default, you can see the default settings aren't going to work for what I want to do here. I want to define this into something more closely towards real world scale for building assets. So I got to set the units here, nothing too huge, but I want to make the size of my grid to be 100 units.
What that actually represents if we just zoom out here and move this out of the way, is that we're working with this grid here to be 100 units. This means that this area here actually represents 100 units or 100 centimeters as does each area here. So, essentially 200 across and 200 back. But this section of the grid from the origin out is 100 units lengthwise and widthwise. Now I want to define my grid lines and I want to have those every 10 units.
If I hit Apply, we'll see now that we have those every 10 units but the problem is our subdivisions are set to five. Put that down to one, and we'll hit Apply again. Now we're starting to get something that defines our overall real world scale. Now, what does this mean that I've set it to? We know that this box in this area represents 100 units, so that's 100 centimeters and we know that we have grid lines every 10 units. Each little box here, each little square you see represents 10 centimeters.
I have one subdivision, meaning that, all we're going to see are those units of 10. That's perfect. This is the way I want to work with it. But if I'm building something a little smaller and I really want some accuracy or even that visual ruler, I can set my subdivisions to divide everything to exactly down to the centimeter. You can see how dense it gets. This is where I might want to change my grid lines and numbers to something darker. And now I can see that I have the black lines representing 10-centimeter increments but I also have these little subdivisions representing every single centimeter.
I got to switch this back now just to, one, just to be a little visually easier to see for our demonstration here. We have this chair. I know that that's built to a proper real world scale and I built it by aligning my grid in the same way that I have here. I'm just going to hit Apply, and actually, Apply & Close and get rid of that window. Now, let's calibrate this or let's test this and make sure that our settings here in our package that we're using, again, whatever you're using. And in Unreal, calibrate or configure.
So I'm just going to do something really simple. We'll create a polycube. This is where we want to be able to calibrate and make sure that the units I have in Maya are the same as I have in Unreal. I'm going to create something that's a 100 centimeters across or for that matter, 100 centimeters all around on a cube. And we'll just hit Create. And that is essentially one meter in each direction. A couple of things on that. Let's just bring this up so it's just sitting on the grid. There's my chair and now it's starting to look like well, real world.
That certainly is, you know, this represents a meter high and a meter wide and that chair certainly fits within the realm of proper scale. A couple of things that are useful within Maya, and most packages have a tool like this. If you're ever in the middle of modeling something and you don't want to have to count everything out, you can simply go into create a measuring tool. This is where you can go, Create, Measure Tool, Distance Tool. What I like to do is hold down the V hotkey which accesses these little magnets up above, and if you press V, you'll see that it'll grab the point magnet.
This will let me stick this to the point on the edge of this cube. And while holding it down, I can get both. We can see that that represents 100 units or in our case, 100 centimeters in height. The same would be true of course with the width. I'm just going to get rid of that. We get that out of there. Good, now we have our 100-unit cube. What do we want to do with this cube? I'm just going to export this guy out, so really what I'm going to do is just export this selection as an OBJ just for the sake of demonstration here.
I'm going to put it to desktop. I'm going to call this one my Maya_1M_cube. I'll set this to the desktop and we'll just save that out. Now I'm going to switch over to Unreal. I'm going to bring that cube in. So, just sitting here in Unreal, we're simply just going to right-click and import, and I'm going to go to the desktop and there's my Maya_1M-cube. I'll click Open, it's going to give me my Import Options. You all just import all.
It's going to tell me it really wishes I'm using FBX because I don't have any smoothing groups here. That's fine. We're going to cover this later, so we don't need to be concerned with any of that right now. But what I want to do now is take this cube, drag it out into the scene. Let's just bring it up here. Just a little tip, if we bring this up and in my demo scene that I'm working with, if you have access to the exercise files, I've just placed a simple floor. What you can do is hit End and at any time that'll snap that down to the floor. So let's just move this guy over here a little bit out of the way.
Now, let's calibrate it, let's configure. Let's make sure that that one meter cube from Maya is the same as the one meter cube from Unreal. We're going to go into our Basic, not the Geometry. Those are brushes, right? So we don't want to get into BSP brushes. I'm going to use Basic and we'll use Cube. If I just grab this and drag this out, we'll bring this up and we'll hit End, and we'll bring this into the environment. Let's line it up beside our cube. By default sometimes, depending on how you have your settings calibrated within Unreal, you may find that the size of your cube may actually be set to 200 units.
This case here, mine is set to simply 100 units. There, we're working with one to one scale as we can see. So that our scale is now in alignment here within Maya and Unreal. This is useful because I know now that when I'm building everything in Maya, it's going to align exactly to Unreal. That's just a quick overview of how we want to work with units and scale for Unreal Engine 4.
- Defining project goals
- Creating an Unreal Engine 4 (UE4) project
- Adjusting first-person project settings
- Creating effective assets
- Exporting assets for UE4
- Importing assets into UE4
- Placing assets in a scene
- Adding and editing collisions
- Working with textures
- Creating a basic material
- Adding a post-process volume