Up until very recently, the job of rendering graphics has been left up to graphics processing units (GPU), which have extremely large bandwidth ideal for processing complex 3D images and converting them to pixels on the screen using rasterization and various shaders.  However, many electronic devices do not have powerful GPU’s, yet their CPU may be quite capable.

With this in mind, developers are starting to looking in the prospects of using ray-tracing, which is an entirely CPU dependent process, to render graphics.  As we know from project 1, ray-tracing a small image may be a piece of cake, high resolution images take substantially more time to render.   Fortunately, mobile devices have relatively small screens, meaning that high resolution rendering isn’t needed to make an image look good.

In his Intel Research Blog, Jeffrey Howard discusses the potential for 3D games to be rendered on portable devices using the CPU for all the intensive processing. Jeff shows that scaling the image down from high definition(1280×720) to reasonable portable resolution(480×272), CPU requirements are cut drastically, only 8% of what it would be at 1280×720.  At this lower resolution, the Sony* VAIO* UX Micro PC is able to run Quake IV at 25-45 frames per second. While this isn’t blazingly fast, the game would certainly be playable.

The beauty of ray tracing is that the images it renders are incredibly accurate and fast for that level of precision. Moore’s law no doubt gives us hope that in the not too distant future, CPUs should be able to handle ray tracing even high resolution graphics at very easily.  This will make virtually all of our devices capable of rendering real-time graphics with overwhelming processing costs.

References:

http://blogs.intel.com/research/2008/02/real_time_raytracing_in_your_p.php
http://en.wikipedia.org/wiki/Graphics_card