Category: Elizabete: hat, fruit or flute

VR handmade drawings: enlarging the view I mentioned the VR art based on handmade drawings on my home page. But, what is it exactly a VR (or 360) drawing? Why am I so interested on them?  I’ll try to explain a bit about it in this article. Although, I must warn you: we will need more than one post! When we do a “classical perspective”, we use what we call a drawing plane. In that plane we re-present in 2D, the points and lines that compose a specific scene of a 3D environment. If we do a parallelism with photography, we always capture an image within the boundaries of the film or the sensor, right? In the same way, the drawing plane limits our composition.  But, what if we want to expand our vision and capture the full panorama around us?  Here is where VR drawings come to help us. A VR drawing represents all around the observer’s point of view. Not just a limited window. Digital VR art: a full 360-degree panorama made in ink and watercolour © Lufo Art, 2017 Photographic panoramas The representation of a full panorama is something well-known in the field of photography. The way to solve a wider picture is to stitch many individual pictures taken with different angles, thus covering a bigger field of view (FOV). The bigger is the angle that the camera captures, the less is the quantity of shots we need to cover a certain FOV. Currently, the technology gives us the possibility to take a 360º per 360º picture with just one shot. These cameras, such as the “Insta360” camera, use many “fisheye” lenses at once. Once the panorama has been generated, we can navigate it and perceive it in an immersive manner. We create such an immersion by putting a surface around the observer, and then covering it with the panorama. The two most used surfaces are the sphere and the cube. Therefore, we can say that in a full panoramic representation the drawing plane changes to a spherical or a cubical surface.  Equirectangular projection The equirectangular projection is one way of mapping the surface of a sphere. This means, it is a way of flattening a 3D shape into a 2D image.  We use the equirectangular format, for instance, to represent the world. In a world map, we can easily notice big distortions, specially in the poles. In fact, Antarctica, Russia and Canada have a shape more elongated in the map than in the reality. This deformation has been analysed and studied through indicators such as the Tissot’s indicatrix. Now, look closer to the equirectangular picture that I took in Lisbon. In this full panorama you can see odd curves and weird building shapes. Yet, if we build a sphere and cover it with the panorama, all lines will look as they should. An equirectangular photography from my ex room in Lisbon © Lufo Art, 2019 Cubical projection​ The cubical projection (AKA “cubemap”) is one way of mapping the surface of a cube. It is used, for instance, to generate scenes in video games (see skybox). In contrast with the equirectangular format, straight lines are represented as straight segments and not as curves anymore. Furthermore, although there is some kind of deformation, it is “more known” to our eye. Indeed, on each face of the cube we have a classical perspective. On another perspective, we could say they are six individual pictures framed in a squared sensor.  But, all that glitters is not gold they said. As everything in this world, the use of the cube has also some cons. For instance, it has the big disadvantage of being a discontinued map. Focus on the image of my ex room in the cubical format. You will notice that is not that intuitive to connect the upper part of the righter face with the upper part of the middle-up face.  Another disadvantage is the odd way that lines break when they cross from one face to another. Take for instance the buildings on the picture: they converge to some point on the righter face, they are more or less straight on the centre-right face, and then they converge again to some another point on the centre-left face… Still they are representing the same block of buildings!  Cubical panorama from my ex room in Lisbon © Lufo Art, 2019 On drawing practice So, we just saw that the equirectangular and the cubical projections are used for photographic panoramas.  But, what if we want to draw a building, show it through its outline, instead of using the billion colour points automatically captured by the camera?  What if we want to do a panorama of a surreal world that does not exist? Good news mate, we can do it!   We can generate our VR art by drawing either in the equirectangular or in the cubical format (further on we will explore other projections as well). Once the drawing is ready, we will fold it digitally onto the 3D sphere or cube, and then we will be able to navigate our artwork … from within! This way, we can create artworks reusing a technology mainly developed for photography and video games. We will use their tools to navigate and share our art, such as the VR plugin for panoramas embedded in Facebook. Anamorphosis​ We saw that both projections have either odd deformations or weird ways of breaking. In both cases, these particularities make all the sense once we cover the correspondent 3D shape with the drawing, and then we place the observer in the central point of it. From that point, you will see every represented shape perfectly reconstructed, and you will notice neither curves nor breaks.  In more rigorous terms, an anamorphosis is a set of two steps: a projection onto a sphere, and a cartographic operation of flattening that sphere. For a far better and more detailed explanation, you can check this work by António Araújo, who has been my mentor since 2018, PhD advisor and a wonderful friend. António has a large and very detailed research specifically dedicated to spherical anamorphosis that you can check here. Let’s use an example to understand better what an anamorphosis is. Pay attention to the original artwork “Elizabete, hat, fruit or flute“: Elizabete: Hat, Fruit or Flute? Equirectangular drawing in watercolours and ink ©…
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