Thinking In 3d

To develop your 3D model (through a 2D interface) is fun, (once you develop humor regarding your Blender learning curve ;) but it requires some geometry to handle it.
Most of you will know, but to enter thinking in 3D - working with 3 axes, orthogonal and perspective views…, some might appreciate going back to the very very start and recall what allows Blender to calculate a model: That each point in space has a defined numeric location x=, y=, z=.

Axes, Global Origin and numerical location of a point in space

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First 2D, a plane:

"What are x and y axis ?" Imagine a class of geometry-learning novices.
All have the same squared sheet of paper in front of them: 10 units wide and 20 units high.
Everyone will set a dot at the same place if the teacher says: "Your Origin is on the left lower corner of your sheet: Count 3 units to the right from the left lower corner, then 7 units up from there, and draw a dot at this point."
Seen fom above, here (Top View if orthogonal/perpendicular): "Left to right" defines one axis. ("x-axis")
"Top to down" the other. ("y-axis")
The Origin is where they cross, the arrows just symbolize the axes, which are infinite.
x and y axis, orthogonal to each other and the origin where they cross, help to define "length" and "width" of a point on a plane.
Units help to define the exact place of a point on a plane.
(Here: x=3, y=7)


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In 3D space:
…there is a third axis to this "coordination system", ( "z-axis") that defines the height "above the sheet", and the axses reach beyond the origin into infinite.

The "Global Origin" (defined Numerical Scene Center, where all axes cross) and the 3 axes simply help to calculate, or define an exact numerical location for each element of your work. The initial Blender file is called scene, because you can animate your models, and add subsequent scenes, but that comes later.
The file defining main coordinate system is called "global". A point at this file center/origin location has the coordinates x=0, y=0 and z=0.

The coordinate system and "a point leveraged above the sheet", along the z-axis, looks like this image to the right. (To get comfortable with Blender, displayed on the Blender Interface)
When you open Blender, the default scene displays a cube with its center at the "Global Origin", the very center of your complete scene or model.
The three axes crossing at Global Origin chuck the virtual space/world you are working in.
All objects you add to a scene have their own local origins, (originally the median point of an added object) but first step is to see that these local origins can be located from the "Global Origin", and what the global origin is.


User Ortho and Perspective View

flickr:5058047034 flickr:5055414653flickr:5055902098 Once familiar with the 3 axises, we talk about Blenders' view perspectives.
Above you see two display versions.
"User Ortho" displays parallels as parallel, which is "more true" to the geometry of your model than:
"User Perspective", which displays, more familiar to our eyes, parallels meeting at vanishing points, (if you would extend them into infinite.)

When working on models, you will find yourself toggle between the two perspectives, to change between easier working, and more realistic view.
(The shortcut to switch, or toggle, is 5 on your NumPad, the Number Pad on the right side of your keyboard if you don't use a Laptop.
This will be repeated, so don't worry, but it leads you to the logic of Blender keyboard shortcuts, as 5 is positioned in the center of the crucial shortcuts on the NumPad.)

You are out for a realistic image, but to create it properly, you will need to work on different 2D views, simplified by eliminating one axis: by looking straight against it (perpendicular).
The "User Ortho" Image intends to show you, how these main 2D Views, Top, Front and Side View look at the model.


Top, Front and Side View

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Before "3D - software" was available, architects had to describe a 3D model based on 2D plans.
By drawing the exact plan of orthogonal views: Top View, Front View and Side View, this was possible, as they, togehter, define the shape of a symmetrical model by describing 3 axes by multiple relevant 2D views.
More complex models needed the complementary sides ("Bottom", "Back" and "Left Side" in Blender), and Sections to become readable and realizeable plans.
The developments in architecture since 3D modeling software is available, give a great expression of how strongly 3D-creation software has empowered designers to realize more complex shapes.
While general artistic modeling doesn't need to be as precise as architectural plans, you will constantly use orthographic views to create your model the way you want them and will quickly get comfortable to think in these 3 (6) orthographic views.

When you see the axes point through the cube in the images, you see that looking straight against them ( =90° to the two other axes) allows to simplify the view onto the model by displaying the 2Dplane chucked by the two other axes, thus displaying one single orthogonal view.
The cube helps to see the logic, that you look at a plane defined by two axes from each view, and "Suzanne", the Blender Model-Model, displaying how different these views onto the same object can look, helps to point out how these (shortcut-recallable) orthogonal views facilitate your working in 3D space:
While working orthogonal views, you limit the repositioning of objects or object parts to 2 axes and have thus more control.

You will use these 3 (6) orthogonal views to work easier and have more control in modeling, as you can do adjustments in only two dimensions, but you will not be restricted to these displays - and thus be able to translate your wildest imagination or prototype into a 3D model.


The idea to start with an introduction to "Thinking in 3D" before describing the Interface was insprired by this Wiki section with the same Name of the well-known Wiki "Blender 3D: Noob to Pro" - where this access is taken far deeper than here - read (on) there, or proceed to the Blender Interface.