BigDaveDev – Honours

We were issued a task in class today to complete a worksheet with the aim of guiding us towards a research topic and ultimately a research question.

First I must state the topic of interest.

I have a keen interest in landscape photography and lighting composure is a key aspect in getting the perfect photograph.  In particular, sunset and sunrise are very pleasant effects.  I am interested in mimicking these atmospheric conditions in an interactive environment using post-processing techniques.

Currently the issues surrounding these post-processed effects is efficiency in real-time.  Various post-processing effects are used in Adobe Photoshop and The GIMP, where time isn’t really of the essence.  With atmospheric effects – such as scattering – game programmers and artists have traditionally used rough approximations due to computational expense at the hands of mathematical complexity, leading to less believable – and thus less immersive – environments.  However, these effects are becoming more popular now due to better hardware.

As stated I intend to mimic atmospheric scattering effects by applying it as a post-processed effect.  This principally means taking a screenshot of the framebuffer and attaching it to the depth buffer and applying this texture to a quad the size of the screen.  From here it is passed straight to a pixel/fragment shader where the effects are applied.  I will primarily stick to the methods outlined by Preetham in his 1999 SIGGRAPH paper “A Practical Analytic Model for Daylight” as the techniques he outlines have remained virtually unchanged.

There are two ways to implement these techniques:

1. The traditional CPU and GPU combination
2. The new GPGPU – General Purpose GPU – methods

In this project I will be looking into method 2 using NVIDIAs’ CUDA technology.  Due to lack of access, I will not be able to create an implementation using AMD Stream as I do not have access to a required ATI card.  I would be interested as well in creating a port of this project to a major console – time permitting – such as the PS3 or the XBox360.  However, I doubt there will be much time left over to try and make this port.

The aim of this honours project is to create a visual effect that can be used in games to create stunning and practical depth-cues for vast landscapes.