Game Engine Architecture

39

Some examples of full-screen post eff ects include

z high dynamic range (HDR) lighting and bloom ;
z full-screen anti-aliasing (FSAA);
z color correction and color-shift eff ects, including bleach bypass , satura-
tion and de-saturation eff ects, etc.
It is common for a game engine to have an eff ects system component that
manages the specialized rendering needs of particles, decals, and other vi-
sual eff ects. The particle and decal systems are usually distinct components
of the rendering engine and act as inputs to the low-level renderer. On the
other hand, light mapping , environment mapping, and shadows are usually
handled internally within the rendering engine proper. Full-screen post ef-
fects are either implemented as an integral part of the renderer or as a separate
component that operates on the renderer’s output buff ers.

1.6.8.4. Front End

Most games employ some kind of 2D graphics overlaid on the 3D scene for
various purposes. These include

z the game’s heads-up display (HUD);

z in-game menus, a console, and/or other development tools, which may or

may not be shipped with the fi nal product;

z possibly an in-game graphical user interface (GUI), allowing the player to

manipulate his or her character’s inventory, confi gure units for batt le, or

perform other complex in-game tasks.

This layer is shown in Figure 1.22. Two-dimensional graphics like these are
usually implemented by drawing textured quads (pairs of triangles) with an
orthographic projection. Or they may be rendered in full 3D, with the quads
bill-boarded so they always face the camera.
We’ve also included the full-motion video (FMV) system in this layer. This
system is responsible for playing full-screen movies that have been recorded

1.6. Runtime Engine Architecture

Front End

Heads-Up Display (HUD) Full-Motion Video (FMV)

In-Game GUI In-Game Menus Wrappers / Attract Mode

In-Game Cinematics (IGC)

Figure 1.22. Front end graphics.