Chapter 5. Models and Environment

Most architectural photographs include furniture and props, to present the design in its full glory. To have a similar effect in our real-time project, we load additional models and set them up as properly scaled prefabs, which can be re-used throughout the project. We can place our project in a convincing environment, including terrain and sky.

After we have literally filled the scene with a large amount of objects, it is important to look at approaches to reduce the burden on the system.

This is again a chapter that is more reading and less doing. After all, optimizing performance is usually done by being clever and planning things properly.

In this chapter, we'll cover:

• Loading a model from the 3D Warehouse

• Setting up a basic landscape

• Creating a custom Skybox

• Working with large models

Loading 3D Warehouse models

To increase the impact of an interactive environment, it should contain sufficient detail. Furniture, accessories, plants, cars, and people can enliven the project. Rather than filling the model with every possible object, place some key items on visible locations around the scene. There are several online repositories of models, animations, and textures. The Unity Asset Store is an obvious entry, but do not underestimate the vast amount of online content that is freely available in Trimble 3D Warehouse. However, as the terms of service (ToS) are not fully clear for usage in commercial projects, you might want to rely on other sources or create your own models. You can either download models directly into Unity using the COLLADA format or prepare them first in other software. It is advised to start from the SketchUp model and at least clean up the normals (front/back faces), as explained in Chapter 1, An Integrated Unity Workflow, before exporting into Unity and...

Setting up a basic landscape

There are multiple approaches to add landscapes in an interactive scene:

• Unity has a dedicated Terrain tool, which is easy to get started with. A terrain is a large subdivided plane, where vertices can be lifted in the Y-direction: a so-called height field. While it takes a lot of effort to fine-tune to perfection, it provides the following interesting features:

  • You can paint the height using brushes

  • You can also paint the materials using texture maps

  • You can add accessories, such as trees, bushes, and grass, which can move, as if the wind was blowing them

• When you already have a grey-scale height-image for your terrain, maybe made in Photoshop or containing real-world geography data, you can import this as a raw image. Refer to the documentation on: http://docs.unity3d.com/Documentation/Components/terrain-Height.html.

• If you created the terrain already inside your 3D environment, it can be loaded as a Mesh, just like any other imported Mesh. However, a regular mesh...

Creating a custom Skybox

When you want to include a credible environment, you can use the Skybox tool. This looks like a large cube, with seamless texture maps of skies placed on the inner side. By setting it around the scene, it follows camera movements and appears as if the whole sky surrounds your scene. There is a default package included with Unity that you can use (Assets | Import Package | Skyboxes) that contains about nine examples. A Skybox can be activated in two places, as shown in the following screenshot. You can activate a default Skybox material in the render settings (Edit | Render Settings). You can also define a Skybox material for a particular camera, by adding the Skybox component to it (Component | Rendering | Skybox).

It is possible to create your own Skybox images in almost any rendering software. Define a camera and position it perfectly horizontal. Set its viewing angle at 90 degrees. Record a six frame animation, with the camera orientated to one of the six cardinal...

Optimizing scenes and models

While the performance of Unity running on current generation computers and handheld devices is still increasing, there are limitations to the amount of geometry you can place in an interactive scene. Especially trees, cars, curved models, and other objects with many polygons slow down Unity, sometimes dramatically. The following screenshot shows how to activate the Stats button on the Game view, which gives some insight in how much work Unity has to do.

We try to reach at least 30 frames per second (FPS) for smooth display. In practice, we hope to attain 60 or more and drop down to 30 as a worst-case scenario. However, don't be too fixated on this number, as it is not an exact prediction of how the application itself will run, for example, on a tablet or in the Web Player. The Unity Wiki provides a utility script for that purpose. For more information on FPS visit: http://wiki.unity3d.com/index.php?title=FramesPerSecond.

Luckily, Unity itself does some optimization...

Summary

While this chapter required more reading than doing, it contains several pointers to procedures to improve your project. We can load additional geometry, to enliven the scene. You can even add detailed terrains and trees and a nice sky image.

However, this all comes at a price; that is, performance may suffer. So the last few sections looked at several approaches to lower draw calls and increase the amount of frames we can display per second. It is also obvious that a pro-license simplifies many of these optimization techniques, but with some experience and a few helper scripts, there is a lot you can improve using the free version as well.

Get ready for our next chapter, on further improving the use of textures and shaders.