BigDaveDev – Honours

Introduction

Atmospheric effects in games are becoming increasingly more popular; however some implementations are less efficient than others, giving arguably better results – (Tomoyuki et al. 1993) vs. (Preetham et al. 1999) for example. These models can be performed on a per-pixel basis to provide very realistic looking skies in games. It was suggested in an e-mail discussion with Damianno Iannetta of Rare on 7^th October 2009 that this project should steer itself toward the model proposed in (Tomoyuki et al. 1993) and as such, this dissertation will be focusing on an efficient post-processed implementation of this technique for PC and/or PS3, making the most use of hardware – i.e. GPGPU and Cell for PC and PS3 respectively.

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This weeks task is to actually arrive at a research question – by no means an easy task!

I have formulated several possible questions thus far and all are related to the topic of atmospheric scattering, as this is my main topic of interest.  I shall list them below:

• Can atmospheric scattering be used accurately in computer games?
• Is it feasible to include atmospheric scattering in computer games?
• Can post-processed effects – such as atmospheric scattering – be used in computer games without hindering performance?
• Can post-processed effects – such as atmospheric scattering – be used in computer games without negatively affecting overall performance?
• Can atmospheric scattering be implemented efficiently in computer games?
• Can atmospheric scattering be used as an effective depth cue in computer games?
• Can atmospheric scattering be used as an effective enhancement to traditional global illumination models?

While the last one holds the most interest for me, I do not think there is enough time to play with this question as it would involve the use of radiosity, ray tracing or photon mapping.  With that in mind, I feel that the question that will allow me to explore atmospheric scattering and post-processing would be the third-last question:

“Can atmospheric scattering be implemented efficiently in computer games?”

With this particular question, the suggested scope should be small enough to investigate GPGPU techniques and post-processing as well as provide me the choice of using either Preetham or Nishitas’ method for the atmospheric scattering model.

It was also brought to my attention earlier today that using Nishitas’ model would allow an appropriate use of GPGPU techniques as there are lots of variables to compute over several frames.

On a final note then, the research question I am putting forward is:

“Can atmospheric scattering be implemented efficiently in computer games?”

I have installed the CUDA SDK at home and have requested that it be installed in the GameLab at Abertay as well.  Having looked through some of the examples supplied – demonstrating, for example,  real-time ray tracing – I am beginning to understand just how important GPGPU methods could become.  It is clear that harnessing the power of CUDA could be the next stage in game development.

And with the Khronos Group releasing OpenCL in a bid to encapsulate both NVIDIA CUDA and AMD Stream in a similar manner to OpenGL and OpenAL, it is reasonable to expect developers to begin using this in the near future also.

Following are some web-sites to read through to gain a better understanding of CUDA

http://llpanorama.wordpress.com/cuda-tutorial/

http://www.nvidia.com/object/cuda_education.html

http://gpgpu.org/asplos2008

http://gpgpu.org/developer