Feb 19, 2010

Trailer of Amnesia:The Dark Descent

Trailer is HERE.

This link features the teaser of the upcoming game from the talented developers of the Penumbra series: Amnesia: The Dark Descent. I have found this teaser really impressive. This is a good example of a nice sounds, visuals and interactions integration!

You can also pre-order the game. And If they reach 2000 pre-orders before the 31st of May, the game will get extra content! I did not played the Penumbra series excepted the demo but I want to try this one so I have pre-ordered the game.

Do not hesitate to spread the word!

Feb 12, 2010

Fourier Opacity Mapping rocks!

The up-coming I3D conference on interactive 3D Graphics and Games will feature several interesting papers! For instance, this year will features papers such as " Cascaded Light Propagation Volumes for Real-Time Indirect Illumination" by Anton Kaplanyan (Crytek) or "Interactive Volume Caustics in Single-Scattering Media" by Wei Hu. Another paper I found very interesting is the one proposed by Jon Jansen and Louis Bavoil (Yeah a French guy), both at nVidia, called "Fourier Opacity Mapping". I could not resist implementing this nice paper.

Fourier Opacity Mapping (FOM) is about approximating light attenuation through a volume made of particles. Let's consider a spot light: the authors proposed to reconstruct the light transmittance function along each ray using a Fourier series. The coefficients of the Fourier series are stored in the fourier opacity map in light view space. This map is generated using usual particles rendering with transformation in the Fourier basis of extinction coefficients in the fragment program. Then, when rendering the particles from view, the corrected light attenuation for each particle can be recovered. I will not go into the details here. You can read the paper here and my report on my personal webpage. Indeed, you can see a video of my implementation of FOM here.

Here are some screenshots of my implementation (Top: without FOM, Bottom with FOM):

A simple particle chain. Notice the correct order of light attenuation.

Colored light attenuation through a particle block.

A grey smoke volume with some red particles. Notice that the red particles attenuate the light correctly: they only affect the color of particles that receive the light after them.

I know that my screenshots are not really eye candy but they show that this method is really efficient to simulate colored light extinction when passing through a volume of particle. Furthermore, if you want an exemple of good use by skilled artist, just have a look at the game Batman Arkham Asylum which implements this method.

My report is finally available on my website together with demo and open source code. :)
You need a recent video card to run the demo since it uses GLSL 1.5 and render data into 6 buffers in one pass.