Join Craig Barr for an in-depth discussion in this video Exporting final assets for Unreal, part of Unreal Essential Training (2016).
- When creating content outside of Unreal Engine 4 there are a couple things we want to keep in mind. For example, the scale of our objects, the density of our geometry, our UV texture coordinate layout. We want to make sure that we have a nice clean efficient asset for exporting out. All I simply have in here is our exported out mesh from Unreal where we've exported out the landscape and exported out our geometry brush assets to bring in as references for a bit of level setup here in Maya.
Now, a couple notes on this that we want to talk about. We can see that I simply have these assets here, the rowboat, the shed, the lighthouse, simply placed where our proxy geometry is placed. And, all I'm doing in that case, here we can use the car as an example, I'm just importing in the car based on the exported geometry from Unreal Engine and then I can just rapidly or quickly bring this in and the nice thing about working with it in this context is we don't have to be right dead on exact. We're just positioning this to make sure that our assets are going to work within our scene and we can actually export them like this if we wanted them in that specific position.
But, there are a couple things that we may want to consider when doing this. So, in this case here, that's probably going to work out just fine for that car. The scale looks about right. We could always scale it down a little bit more if we needed to, but this is now where we can start to get a feel for the basis of our overall scene, right? So, we can start to see the scale of the objects and how this is going to work within our scene. So, some things to keep in mind. When we're building these assets, this is where we want to make sure our geometry looks good, our textures are laid out properly because we're not going to be viewing this scene typically from out here.
For our cutscene, we're going to come in nice and close so we're going to use cameras within Unreal where we're going to be able to see these objects probably at about this scale. Some of these objects we may come up nice and close to. So, you're going to want to make sure your geometry looks good and if you're utilizing textures that, those materials are applied properly so that everything looks quite good in there. So, this is looking good. I'm happy with the overall scale and placement of the objects. Now, just a note on exporting this. We can export this just like we did out of Unreal with everything as one in there if we really want to do that but it's going to really cut back on the flexibility and working with things like materials.
So, this I'm using as a placement for objects for composing a scene and for scaling of the objects. But, it is actually nice if I have in my content browser several different objects available where I can drag them in individually and have their own material network, which we can jump into the material editor and be able to dial in specific materials for it, so we do want to keep these objects separate. Now, for exporting out objects I should point out a couple of different basic things. It doesn't matter what package you're using whether it be Maya, Cinema 4D, Blender, 3ds Max, whatever it is, it doesn't matter.
The basics here still apply. So, two formats that you typically going to work with. Number one is .fbx. FBX works well for sending over models with all of your UVs laid out. You can also embed media so you can keep the textures directly linked to a mesh if you want to. Just a word of advice on that, it's typically advisable you don't embed media and we'll take a look at the setting in there in a moment. As well, for some reason you cannot work with FBX you can always use good old .obj format and that's going to take care of your static mesh and your texture layout.
It won't handle anything more than that, where as FBX if you have animation or deformation on a model you can export and bake that animation over in that file format as well. So, let's take a look at a couple of different export options. Now, we're not going to care about exporting this landscape out because we already have that in our Unreal environment but being able to have it here in Maya is really useful to be able to just kind of set up the scale and the placement of these objects. So, we don't need to worry about that but we may want to worry about our actual specific assets that we built here to export over. So, what we can do if I take this car for example and go into File Export Selection here in Maya I'm going to make sure I'm defining FBX export.
We'll go to Export Selection and I'm just going to make sure that this goes into my models directory in my actual project directory is where I'm saving this as well. This one should probably go into the props directory here. Now, a couple things with the FBX export. We want to make sure we have our smoothing groups defined so that we bring over any Normals setup that we've done on there, so Smoothing Groups you want checked on. Smooth Mesh and Reference to Assets Content we don't need this on for this case here, it's on by default. It's not going to affect anything if I leave that on.
Now, just a note on triangulation here. If you click this, FBX will take care of the triangulation for you if your model is not already triangulated but it doesn't really matter. You can still export quads and Unreal will work with that. The engine will translate your geometry into what it requires for optimum usage anyway so I wouldn't even worry about that. As well, animation, if you have animation on your asset you'll want to turn that on. We're exporting static meshes right now so that doesn't matter. And if we come down here to Embed Media, as I mentioned previously, Embed Media is a way that you can actually create something that has your textures directly linked to your model, so it's actually this portable asset, this portable model with all of its texture maps with it as well.
That's great and that's really good for portability, it's actually advisable that you split them. So, keep your model separate. Save it in the models directory and keep your textures separate. Save them in the textures or textures map directory. And that way, you have a little more power and flexibility to work with each format in Unreal whether its how you're going to compress that data or working with different scale and, at anytime, it's nice to be able to affect or edit to that texture map and have it updated so that your project directory will see it as well so I would advise just keep it separate and don't necessarily use Embed Media.
Down in the advanced options here something to consider, by default typically in Maya here the FBX export is going to have an Axis Conversion with the Up Axis of Y. Now, you can change this to Z or Zed simply because Unreal uses a Z or Zed Axis so you may want to do this in here. If you don't, it's not a major deal but you will have to rotate everything or flip everything on its X axis by 90 degrees so that everything is facing upwards to what you want. That ability or that option does exist here within Maya for the export options in FBX as well.
So, that's basic overview on that. We would simply export out our objects here and again, we can make sure that this exports out to the exact location as we have here in Maya so that it's in that exact spot with that transformation that's happened so that when we bring it in we can have it here or we can keep it zeroed out with all these assets and deal with our placement and our scaling directly within Unreal Engine. We're going to take a look at how we can do that in Unreal Engine as well. So, that's a basic overview there of things to keep in mind when you're exporting objects for Unreal.
Unreal is flexible in the file formats that it will take, but it's advisable you start with number one fpx and if for some reason that doesn't work out for you, you can certainly use obj for static meshes.
- Customizing the Unreal UI
- Creating a new project
- Creating landscapes
- Blocking out levels
- Assembling a scene
- Working with materials and lights
- Adding post-processing effects
- Defining bodies of water
- Adding atmospherics, foliage, and wind
- Working with the Blueprint editor
- Creating cinematics
- Monitoring performance
- Packaging a game for distribution