Software Occlusion Culling

Intel Corporation

---

Features / Description

Most realistic 3D scenes contain objects that are occluded by other objects in the scene. Typically, these occluded objects are still submitted to the GPU for rendering, only to have all of its pixels rejected by the z-buffer later in the pipeline. The objective of this sample is to improve performance by lowering the computational cost of occluded objects in the scene. The technique divides scene objects into two groups: occluders and occludees. It uses a software rasterizer to draw the occluders to a depth buffer. It then tests each occludee for occlusion by rasterizing its bounding box against this depth buffer. The sample further improves performance by reducing the number of processed occluders and occludees with frustum culling. It is also optimized with SSE, multi-threading and pipelining. On a 2.3GHz 3rd Gen Intel Core Processor (Ivy Bridge) system with Intel HD 4000 graphics, software occlusion culling achieves up to 9X performance speedup compared to a non-culled display of the sample scene.

System Requirements

Hardware:

• CPU: Intel® Core™ i5 or better suggested
• GPU: Microsoft DirectX* 9c capable graphics card
• OS: Microsoft Windows* 7 or Microsoft Windows* 8 (x64 recommended)
• Memory: 2 GB of RAM or better
• USB or integrated camera technology

Software requirements for binary:

• Redistributables: Microsoft Visual C++* 2010 SP1 Redistributable Package (x86 or x64), DirectX End-User Runtimes (June 2010)

Software requirements for building:

• Compilers supported: Microsoft Visual Studio* 2010 w/ SP1, Microsoft Visual Studio* 2012, Intel® C++ Compiler version 11