Thursday, December 26, 2019

Optical Flow

When we look at the world, it's rarely the case that our head is held still and the scene in front of us remains static, too.

When we're driving a car, the scene flows outward from the vanishing point straight ahead of us. At the margins of our view, the movement is extreme, stretched, and blurry. 

This phenomenon is sometimes called "optical flow" by psychologists and computer graphics people who need to identify or render moving objects. 

Traffic systems can track the velocity and directional vectors of vehicles as they move normally in space, and they can detect abnormalities such as speeders or aggressive drivers. 

Image via Baldpunk
Often the whole scene is dynamically shifting, with our viewpoint changing to follow a moving person or object. Each part of that larger dynamic system has its own relative arc of action. 

I like to use the term "speed blur" to refer to the blurring of the background when the viewer is moving through space, and "motion blur" to refer to the blurring of a moving object relative to the viewer.

Comic artists, video game artists, and animators are all very familiar with these effects, but it's unusual for painters to try to capture them. There are exceptions, such as the wildlife painter Manfred Schatz.
Manfred Schatz on GurneyJourney


Timothy Bollenbaugh said...

I'd missed the 2015 post on Manfred Schatz, which post referenced Bruno Liljefors. They're a good pair for demonstrating that energetic movement can be implied by the technique of blurring with the brush or by sharp focus choosing an instant of action.

Roberto Quintana said...

Great post James.
This "motion blur" effect goes back to some of the earliest mural art, the Paleolithic murals of Chauvet Cave, in France. In this video from Werner Herzog's documentary film 'Cave of Forgotten Dreams' (2010). (at around 5:55, you can see a bison painted w 8 legs, giving the impression of movement) ,

The ‘Futurist’ painters:

were also very interested in depicting speed and movement, example: Marcel Duchamp, ‘Nude descending a staircase, #2’
‘Dynamism of a Dog on a Leash’, oil on canvas by Giacomo Balla, 1912; in the Buffalo Fine Arts Academy, New York.

“Often the whole scene is dynamically shifting, with our viewpoint changing to follow a moving person or object.”

Byzantine Art, Cubism, and Reverse Perspective are other attempts to explore this shifting dynamic view/pictorial space. -RQ