None of the images below are drawings but the results of rendering true 3D models.
Note: hover over ◊ where present to get pop-up comments.
The 6 images marked † appeared in the 2010 calendar Illusies & Optische Fenomenen, Paul Baars, 2009.
The 2 images also marked ‡ appeared in Amazing Visual Illusions, Arcturus, 2011.
A full description of these .ttf files can be found on the separate fonts page, but they are included here as they are illusons in their own right, and can be downloaded via the links beneath each image. They are distributed under the Creative Commons Licence “BY-NC-ND” option.
The Romans were marvellous architects and engineers, as is shown by their aqueduct running from modern-day Uzès to Nîmes, which has a drop in height of 17m over its 50km length. However, I think even they would have had a bit of trouble constructing these.
The ivy in images 3b & 4b was created with Thomas Luft's free program, available here.
The textures here and above had already been made for use in The Pole Star Inn, so were not deliberately copied from the kind of brickwork featured in Jos de Mey's work.
Such objects are traditionally described as 'impossible' because they cannot be constructed as 3D objects or, when done so as on Oscar Reutersvärd's page, can only be viewed from one angle due to overlapping elements. However, as can be seen from the curious solids section of the Geometry page, it's also possible to have the same object appear to have the same outline and edges when seen from multiple angles, and the 9 cubes which form the traditional tribar are merely seen from an isometric viewpoint. Knowing this, it's then a simple matter of rotating each cube and ensuring that the faces of adjacent objects touch one another; thus a different kind of model is created, which creates the illusion of the objects being at 90° to one another when they actually lie on a plane surface. Note that the small triangular gaps between the corner cubes are not due to them being mis-placed or having flawed geometry, but exist because of the slightly rounded edges.
