Measuring visual length

We want to build a coherent representation of geographical time-space. In such a representation the measurements of length, which I introduced as measurements of the visual length, must be proportional to time-distances. A simple way to check this property of the representation lies in the direct measurement by means of a ruler on the computer screen!

Measuring visual length with the ruler on the computer screen

And the measurement shown that the ratio of the length of long and short routes, here around 2.3 is not consistent with the ratio of speed which is 7.5 when confronting a terrestrial speed of 100 km/h with the mean long haul airline speed of 750 km/h. We still have to work!

Another Blender test

This is another Blender rendered test of the same enigmatic area as in the previous post. Billel Helali has introduced visual effects in a search for readability of the three dimensional structure.

Dark blue cones, white edges, with Blender’s bloom effect

This is three dimensional cartography, hence we are working at the intersection of cartography, with its strict rules, and three-dimensional representation, with a lot more freedom. We want to build the most intelligible image and this is a true challenge. Why not trying to exploit the domain of visual effects? This is the bloom effect of Blender that highlights the white edges. Nice, isn’t it? Probably more for fun than for geographical analysis. But definitely worth sharing it here.

Tests in Blender

We are testing the production of the image with Blender that give way more latitude to control all the three dimensional image parameters. These are first attempts they are far from what we want to achieve but they already give an idea of a final result.

Edges as white cylinders, cones with facets

We had issues to move from the app to Blender: lines without width did not show in the rendered image from Blender; they need to have a volume; we converted these lines into cylinders.

All the Blender work is due to Billel Helali, great work!

I do not resist to leaving it as an enigma: which part of the world time-space is represented here?

First coherent image with cones and edges

Today we finally produced this first image of a coherent geographical time-space representation with air and terrestrial transport modes.
Air links are following the geodesic curve when the distance is greater than 2000 kilometers. Below this threshold the speed of the air service is lower which is expressed by the curving of lines high above the earth surface where the fastest transport occurs.

Still un-projected, a lot to improve in terms of readability, but already the basis of what I had in mind since the start of this project is taking shape. A great day today.

Shriveling untill resembling a chestnut

Concorde time shriveled world
Shriveling time-space relief representation of the world at the time of Concorde 1977-2003 CC-BY A L’Hostis

“And yet it moves”, said Galileo. “And yet this is the earth as we experience it” could we now say, looking at this image.

Produced by a JavaScript code based on the library three.js, with decisive help from Farouk Abdou, this is the first accurately parametrized representation of the global time space, at the time of Concorde (1977-2003), when the maximum available transport speed, that indicates the standard for maximum speed, was 1500 km/h. The principle of construction of the image is detailed here.

This has been, so far, the most intense shriveling movement in transport history, when the maximum available speed raised from 700 km/h with jets to the supersonic speed of Concorde.

Considering, in a simplified model, terrestrial speed of 100 km/h, say on a motorway or by train, the slope of cones takes this geometry. During this Concorde period, terrestrial speed was 15 times slower than the maximum available  speed.

This image is very close to the idea of the chestnut that I announced in 2007. High quality image download link.

The first image of a shriveling world

Shriveled world unparametrized
The first unparametrized image of the shriveled world. CC-BY A L’Hostis 2016

Using the library Cesium, and with great help from Thomas Leysens and Farouk Abdou, this is the first image (in higher quality here) out of this new project, producing a representation of global time space.

Very excited when I first saw it on my computer screen. This is the first time this image, which I had in mind for years, finally materializes.

Unfortunately it has proven very difficult, for me at least, to control cones geometry. In addition in Cesium it is not possible to draw geometries under the surface of the globe. the problem is that, conceptually, the time-space relief map model, everything occurs under the surface.

An exchange with Cesium developers has indicated an alternative choice: the library three.js, which has less limitations for our purpose.

The first time-space relief cartography, analog photography of cathodic screen

In 1994 in the CESA, spatial planning center of Tours University, the first time-space cartography took the form of an analog photo of a cathodic screen of European time-space, as shown on the image. The image was produced by Alain L’Hostis, by means of the computer program MapNod, from the indications of Philippe Mathis.

Time-space relief cartographic representation of Europe
The first time-space relief cartography, analog photo of cathodic screen, Europe CC-BY A L’Hostis

At that time the model is not finished as illustrated by the incomplete bottom of facets. A triangle is missing but all the networks are visible, since they form the structure on which the relief is drawn.  Relief comes as a surface along the deformed road network. Three terrestrial transport modes are represented here: classic road, motorway (mode 6) and  high-speed rail (mode 3).

By lack of available color printer in the CESA laboratory, analog photo of computer screen was one of the few possible options to realize this cartography. Later we used print-screen software to produce bitmap images, and even later developed the software MapNod to produce direct vectorial images in the WMF format.