[Ruphin]

A technique similar to what you described is sometimes used in graphics engines for games. It's generally referred to as "motion blur". I think what the engines actually do is determine if an object has a velocity relative to the camera, and apply a stretch and blur effect on the object based on the direction of movement. This is relatively cheap (don't have to render many times times per single frame), but comes with a downside that the blur effect "overshoots" which can look weird when an object suddenly decelerates.

[hnuser123456]

In the source engine at least, you can playback recorded gameplay at arbitrary timescales, and at one point I had it play back a scenario at several hundred FPS equivalent and used some virtualdub plugin to merge batches of frames, and indeed the footage looked much more continuous than just a single, infinitely fast exposure per displayed frame.

[kllrnohj]

Note that games have 2 different types of "motion blurs" - there's camera motion blur (blur the entire scene based on camera movement), and per-object motion blur (blur the object, really the pixel, by its velocity).

The former is often hated because it causes motion sickness, but it can help for rapid camera moves on low framerates. The later is generally just pretty good looking.