As you very well may know, in movies and games we fake continuous movement by exchanging individual pictures at a rapid pace. We call these pictures frames and the pace in which we replace them (frame-rate) is expressed in frames per second (fps).
Most movies in theaters have a frame-rate of 24 fps, but for games the frame-rate is a lot higher (ideally at least 60 fps). Why this difference? Let’s do a little experiment:
Make sure you have a dark background on your computer desktop. Now move you mouse cursor around the screen as fast as you can and first focus on the background, then try to focus on the cursor. What do you see?
In real life (with sunlight) you would see an object move in one natural motion. But if you look at your cursor, you’ll see it at multiple locations at once and you can hardly focus on it.
The thing is, your cursor is updated at 60 fps. This means that even 60 fps does not guarantee smooth animations!
Even on a screen that updates at 120 fps, you’ll not see the cursor move in one smooth motion. Instead, the distances between the separate cursors will be the half the size as you see them now.
But how come movies get away with only 24 frames per second? First of all, they try to prevent objects moving very rapidly on screen as your cursor just did. This is why you do not see a lot fast panning shots in movies.
Secondly, since cameras have shutter speeds, fast moving objects will blur. Through motion blur, a fast moving cursor like we just had won’t display as a few separate sharp cursors. Instead, you’ll see one smudge in the form of a line between the start position and the end position of the cursor.
Since the photo-receptors in our eye do not react to change of light instantly, we perceive fast moving objects blurred as well. That is why the blurred 24 fps movies still look smooth.
To test what I just wrote down, go to this website and set the fps of the two footballs to 24 fps; one with motion blur enabled, and one with motion blur disabled. You’ll probably notice it’s pretty annoying to try to focus on the ball without motion blur.
But now back to Caromble!. After what you’ve just read it shouldn’t come as a surprise that we are currently experimenting with motion blur to make sure movement in our game feels smooth. If you’re wondering how, read this presentation.
While it’s still work in progress, here is a sneak peak: