Game Engine Architecture

36 1. Introduction

Low-Level Renderer

Primitive

Submission

Viewports &

Virtual Screens

Materials &

Shaders

Texture and

Surface Mgmt.

Graphics Device Interface

Static & Dynamic

Lighting Cameras Text & Fonts

Debug Drawing

(Lines etc.)

Skeletal Mesh

Rendering

Figure 1.19. Low-level rendering engine.

Resources (Game Assets)

Resource Manager

3D Model Resource ResourceTexture ResourceMaterial ResourceFont ResourceSkeleton ResourceCollision ParametersPhysics World/MapGame etc.

Figure 1.18. Resource manager.

1.6.8. Rendering Engine

The rendering engine is one of the largest and most complex components of

any game engine. Renderers can be architected in many diff erent ways. There

is no one accepted way to do it, although as we’ll see, most modern rendering

engines share some fundamental design philosophies, driven in large part by

the design of the 3D graphics hardware upon which they depend.

One common and eff ective approach to rendering engine design is to em-

ploy a layered architecture as follows.

1.6.8.1. Low-Level Renderer

The low-level renderer , shown in Figure 1.19, encompasses all of the raw ren-

dering facilities of the engine. At this level, the design is focused on rendering

a collection of geometric primitives as quickly and richly as possible, without

much regard for which portions of a scene may be visible. This component is

broken into various subcomponents, which are discussed below.

Graphics Device Interface

Graphics SDKs, such as DirectX and OpenGL, require a reasonable amount of

code to be writt en just to enumerate the available graphics devices, initialize

them, set up render surfaces (back-buff er, stencil buff er etc.), and so on. This