#05 – Explanation on perspective and spherical panorama grid creation

Heya ! I am feeling a bit sick today, I guess I needed some more sleep since I was back to Belgium.
Gosh, and I want to eat a lot of chocolate today, don’t ask me why (chocolate and tea make me drunk, let me drown my sorrow in these delicacies). Oh well.
Today’s subject will be something a bit different from the quadcopter.
I wanted to draw panoramic scenes a long time ago when the first photographic stuff was created.
So here we are today:

  1. Lift my little bum from the seat and get some motivation
  2. Making my own perspective grid with blender
  3. Exporting the grid in photoshop
  4. Drawing on the grid

Perspective is something really messy if you can’t understand basics geometries and human’s perception. So let me explain it first so you can understand a bit how it works. You need to imagine your eyes like a camera.

First of all, when you see an object in this reality, you can touch it and get many points of view from different angles. The position of the observer determinate how you will see an object from one side or another. But how to draw an object when the observer always move in a different position from an object?

Horizon line, vanishing points and vanishing lines.

1) The horizon line determinate the drawn object.

Let me explain: horizon line is an imaginary line where sky and earth touch each other. For example, when you are above a tower, or underground, there will always be an imaginary line that will be at the height of your eyes! That’s the reference line when you want to draw something. If you look above, the horizon’s line will be below, and if you look down, the line will go up! I know, it’s very abstract but you need to understand that rule before going ahead.

2) The second thing you need to know are vanishing points.

  • Depending on where you are, vanishing points will deform the view of an object. If you see a cube from the front, you will only get the view of one face, a square won’t it? That’s the one point of view perspective.
  • But when you look at the side of the cube, you will see two faces. The edges are deformed, even if you know they are squares, they look like trapezoidal shapes. That is because edges are connected to two differents vanishing points (since your squares aren’t parallel to each other). Two-points perspective first common representations can be found on medieval textbooks.
  • Three points perspective literally took two points perspective and add one more vanishing point for a diving view or a view from below. It is like you see your two points perspective cube and look a bit from above (at this point, you can see three faces but each face are different from each other because all the edges aren’t parallel to each other).
  • Four points perspective can be called by “fisheye perspective” and is a bit fishy (sorry for the pun). It is basically the deformation of the object when you look at it through a fisheye lens (your eye is also a fisheye lens, so when you look at something, you actually look in four points perspective).
  • Five points perspective is the same as the fisheye stuff but with a variation angle from the view.

3) Finally, the imaginary line that joined edges to the vanishing points are the vanishing lines.

In the examples above, I explained to you that edges of the cube deformed the faces. If you follow the edges to the vanishing point by drawing a line, you can see that all the edges paralleled to each other in the reality will join at the vanishing point. These imaginary extension lines from the edges to the vanishing points are called “vanishing lines”.

When you can fully understand these type of perception, you can actually work on the spherical panorama view.

Spherical Panorama view or 6-points perspective

The Spherical Panorama is a view with 4 cardinal directions (North, Est, South, West) and an axis where the observer stand (above: Zenith, and below: Nadir). It is difficult to draw on this kind of “virtual reality” space because human’s eyes can’t perceive the deepness of an object unless being able to see it (you can’t exactly understand how deep a box is when you only see two faces for example). So, the best way to understand what you draw is to create a perspective grid.

1) How to create a spherical panorama grid?

Blender will be useful for this part. A 3D model will help us to determinate where is the position of the observer in the space. If we want the grid to be consistent with good proportions, the camera needs to be IN a giant room (a cube). That cube will be loop cut and sliced.
When the cube will be grid sliced, we need to create the opacity of the edge. In the “modifier” of the object, I can change it with the “Wireframe” option.

The object can now be duplicated many times outside of the first cube. That way, we can get a deepness sense of space. When several cubes are placed, I can now use the camera and get an¬†“equirectangular panorama view” that will flatten our cube in 2D.

However, the background of the panorama is still gray so I want to change it. It will help me to know where is the ground and where is the sky. In the “world” tab, I can choose to change the surface.

Surface > Colour > Sky texture

No, I can export the image in .jpeg. Ready to be used in photoshop!

2) Drawing in the Spherical Perspective Grid.

In photoshop CC2018, I can import some panorama layout (in the 3D tab). I still don’t understand how it is possible to draw in different layers because if you move in the 3D layout, the 2D layout won’t move accordingly.
So for now, I tried many things.

One working way to be able to draw on different layers is to check the “texture” tab in the layer options. I can double-click on the .Jpeg I created on blender. A different window will pop out with the 2D texture in the layer, then I can add another layer and work on it without modifying the Grid.

In many failures attempt, I finally get what I want!
If you want to check the result, click HERE.

Enjoy!


What I learned:

  • Using Wireframe modifier (Blender)
  • Changing Sky environnement (Blender)
  • ¬†Camera moves and configurations (Blender)
  • Making a equirectangular panorama view (Blender)
  • Import perspective grid from Blender (Photoshop)
  • Adding new layers to a 3D one (Photoshop)
  • Sketching with difficulties with fisheye persp’ arg. (Photoshop)
  • Dying with a combination of motivation and headache/sickness (#iamsick)

 

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