Cinematic Effects in Source

Depth of Field and Motion Blur together:

Combining the two effects together can bring some quite fantastic effects that can really make the focal points of the game stand out. Not only that, but they also help to remove a lot of the shader aliasing that the Source Engine in particular suffers from.

Valve can achieve this by changing the depth of field on parts of the map that are subject to texture shimmering or shader aliasing, which essentially removes detail from that particular part of the scene.

We have been able to apply this to an entire scene with LOD Bias tweaks for a long time now, but depth of field tweaks will be dependant on the scenario and what does - and doesn't - need to be displayed with maximum details and clarity in order to make the scene realistic and cinematic at the same time by drawing the gamer's attention to the important parts of the scene.



The screenshots above show the effects of the two techniques combined together - you really get that feeling that the scene has depth and is moving at the same time, too. Obviously, it is up to the developer - in this case Valve - to make sure that the two are combined together effectively. They can achieve this using what is known as an accumulation buffer.

Accumulation buffers have been around for a while now. Essentially it means that individual frames are buffered, and stored or "accumulated", so they can be re-used later in the scene with a slightly different render target. This works in the same way as ATI's temporal anti-aliasing: a second sample is taken on a slightly different render target to give a much smoother image when the two are combined together.

The other great thing in the video is the way that the camera shake really works well when motion blur is turned on. The motion blur really helps to enhance the camera shake when an explosion goes off. The screen appears to be fuzzy when the camera is shaking, further enhancing the intensity of the explosion.

Day of Defeat. Accumulation Buffer Motion Blur & Depth of Field

Duration: 25s
Resolution: 1280x720
Filesize: 29.3 MB
Codec: WMV9

Download Locations:

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Update: bittorrent - ALL VIDEOS (~360mb)

The first clip uses both Depth of Field and Motion Blur on the right hand side of the 50/50 split screen. The left hand side of the scene has no effects applied.

Day of Defeat. Accumulation Buffer Motion Blur & Depth of Field - Full Scene

Duration: 25s
Resolution: 1280x720
Filesize: 16.3 MB
Codec: WMV9

Download Locations:

bit-tech.net Server #1 (Removed) - Please use FileShack or the bittorrent.
FileShack mirror

Update: bittorrent - ALL VIDEOS (~360mb)

The second clip is a full screen application of both Depth of Field and Motion Blur, so that you can see how the effects work together on the whole scene.