There are multiple types of blur possible (has nothing to do with "HD").Formless said:The blur effect is very much the same, but the game overall looks worse, making the blur look worse I suppose. I don't get the difference in technique besides one being in HD and the other not
I believe the type of motion blur found in many modern 360, PS3, and PC games relies either on an accumulation buffer or a pixel shader (for velocity based object motion blur). These effects can be applied to the full screen (for camera based motion) or individual objects. Naturally, object blur is more demanding.
This produces something like...
This is designed to simulate camera exposure. When something is captured to a single frame of film, the camera lens is exposed for a certain length of time. If the object in motion is in one location when the exposure begins and another when it ends, you end up with a blurred object.
An older method used commonly last generation involved the simulation of motion blur though blending each frame with a previous frame, so that previous frames are still visible for a moment (I believe this is referred to as "Frame Feedback"). The below example is worst case. At 60 fps moving into a scene, it doesn't look TOO bad, but it's still a far cry from the above method.
Excite Truck is a different beast in that its blurring effect isn't really motion blur at all. It's simply a frame buffer effect, I believe, similar to depth of field, I suppose. It has nothing to do with velocity or motion at all and simply occupies a portion of the screen when boost is engaged. It gives the impression of motion blur, but is in no way related to what were seeing in the Sonic Unleashed video. The two later PS2 Burnout games used this effect as did NFS-Underground.
The Wii has yet to display anything resembling the first method in real time and it seems unlikely that it ever will for a variety of reasons.
I'm no expert on the subject, by the way (not even close), but I've gathered enough information from various readings and certainly have perceived the difference myself.