3D Modeling Introduction PDF

AS2209 INTRODUCTION TO 3D MODELING UNDERSTANDING THE 3D SPACE As we live in a 3D world, we refer to coordinates usi...

AS2209 INTRODUCTION TO 3D MODELING UNDERSTANDING THE 3D SPACE As we live in a 3D world, we refer to coordinates using x, y, and z-axes for geometric purposes. All things big or small that we come across in our daily lives are within this 3D world. Every modeling program uses some kind of coordinate system. A coordinate is the numerical representation of a location or position of something. For building anything, we need a reference system to position and orient objects, be it a house, a car, an aircraft, or a printed poster. This reference system is known as the coordinate system. The Grid The world of 3D graphics depends on a giant “grid” or location coordinate system, to exist. The 3D grid is an extension of our method of measuring distance. Essentially, it is a giant graph that encompasses the entirety of the 3D world. This grid is known as the Cartesian mapping. The grid is separated into three (3) dimensions: x, y, and z. These dimensions are responsible for locating everything that ever goes into 3D graphics. When working with 3D graphics, there are two (2) types of coordinate systems: Y-up and Z-up. Y-up is generally the standard for animation, and Z-up is generally the standard for architecture and engineering. Global and Local Coordinate Systems To understand the setup of this coordinate system, one must first understand how the grid operates. The grid is an infinite set of coordinates that determines where the transform is. If you create an object in any 3D software, it will create a transform that is associated with that object. That transform will then be measured from the world origin in global space. The global (or world) coordinate system is one way to locate an object in 3D space. There are relative locations for every point in space, especially if they are attached to another object. We call this the local coordinate system, which determines where an object is about another object to which it is attached. 01 Handout 1 *Property of STI  [email protected] Page 1 of 8  AS2209 TRANSFORMATIONS A transform is simply a point in space. That point in space can be moved, and anything that is connected to that transform will move with it. A transform has no volume and takes up no space. It is simply a way of determining where an object is in space. Therefore, the transform will be given three (3) sets of coordinates, corresponding to the three axes in the following order: x, y, z. It is written in code form as (x, y, z). One of the backbones of 3D surface modeling are the three key tools: Translate or Move, Rotate, and Scale which refers to moving objects or groups of objects and altering their shapes, proportions, and sizes. These operations are referred to as transformations. Three broad categories of transformations include: Translation (Move) refers to moving an object from one position to another, either in 2D or in 3D. This is the simplest transform. All of the sub-objects of the transform move along, keeping their relative distances from one another (which are their local coordinates). You can translate any object on the x-, y-, and z-axes. These are separated into three (3) channels that can be edited independently. Global and local transformation will be the same as long as the two are aligned. Rotation is an interesting transformation. Rotating an object is just translating it, but around a specific point in space. Therefore, wherever your pivot is, the object will translate itself in orbit, around the pivot. Scale is a transform that changes the relative spacing between sub-objects but increases the space between components. Like the real world, it changes how “big” something is, or how much “space” is between the component that makes up that space. Scale can occur on the local or global coordinate system in a non-uniform manner. The default value for scale is one (1). Changing the scale value to less than one (1) makes it smaller, and values larger than one (1) make it bigger. If you scale an object to zero (0), it will essentially disappear as all of the components that it consists of will be scrunched into a single point in space. 01 Handout 1 *Property of STI  [email protected] Page 2 of 8  AS2209 WHAT IS BLENDER? ® Blender is a free and open-source 3D modeling and animation suite. It is a computer graphics program that allows users to produce high-quality stills and animations using three-dimensional geometry. In the right hands, Blender is capable of producing 3D graphics that plays a major role in video games, industrial design, scientific visualization, and architecture. Being free of cost, users can download Blender from their website (www.blender.org) without paying anything. Additionally, as an open-source program, users can also freely download the source code, or the code, that makes up the program. Because of these strengths, Blender is an ideal program for small animation companies, freelance 3D artists, independent filmmakers, computer graphics hobbyists, and students beginning to learn about 3D graphics. Like many other 3D computer graphics applications, Blender has had a reputation for being difficult for new users to understand. At the same time, however, Blender is also known for allowing experienced users to bring their ideas to life quickly. USER INTERFACE One of the most daunting aspects of Blender for newcomers and seasoned 3D professionals alike has been its unique and peculiar interface. Blender’s interface has arguably been the most controversial feature it has had. 01 Handout 1 *Property of STI  [email protected] Page 3 of 8  AS2209 When a user launches Blender for the first time, they will be greeted with a Splash Screen. This screen will show what version of Blender is being used. This screen will also display a piece of artwork made with Blender, and it will let a user open project files that have recently been worked with. 01 Handout 1 *Property of STI  [email protected] Page 4 of 8  AS2209 Blender’s user interface (UI) is highly customizable. By default, it is broken up into six distinct areas: 1. 3D Viewport The 3D Viewport is where users will be spending most of their time. It is the window onto the 3D scene. Nearly all 3D modeling is done here. 2. Outliner The Outliner panel lists all objects in the project and helps users to organize their scenes. 01 Handout 1 *Property of STI  [email protected] Page 5 of 8  AS2209 3. Properties The Properties panel is located below Outliner in the interface. It consists of the Editor Type dropdown, various buttons such as Render, Render Layers, Object Constraints, as well as Object Modifiers, Material, Physics, and so on. When a button is selected, related panels are displayed in the Properties panel. These panels consist of various parameters to change the properties of the selected object. 4. Timeline The Timeline is located at the bottom of the interface. It consists of the following components: Editor Type dropdown, track bar, time slider, the Timeline menu bar, the Sync drop down, and various buttons to setup animation in the scene. 5. Status Bar The Status Bar can be found at the very bottom of the user interface. It includes helpful hotkey reminders, tool options, a polygon count, and other useful information about the current file. Users can check the status bar often for reminders of how tools work. 6. Top Bar The Top Bar is found at the very top of the user interface. The Blender logo can be seen at the top left. Clicking on it will give users the option to reopen the Splash Screen. The Top Bar includes the typical menu options that can be found in most software, such as File, Edit, and so on. 01 Handout 1 *Property of STI  [email protected] Page 6 of 8  AS2209 The Top Bar also features Workspaces presets, such as Layout, Modeling, Sculpting, and more. These tabs will allow users to quickly rearrange the user interface for different workflows. Other Essential Menus and Tabs 1. Navigation Controls At the top-right corner of the 3D Viewport features a navigation gizmo that is particularly useful when using Blender with a drawing tablet or any other device with a stylus instead of a mouse. 2. Mode Dropdown The Mode Dropdown is located next to the 3D Viewport menu bar. This is the most frequently used dropdown of the Blender interface. The modes in this dropdown are: o Object Mode is the default mode chosen in the Mode Dropdown. This mode is used to create various types of objects such as primitives, curves, surfaces, and so on. This mode should be active if the user intends to select objects in the scene. o Edit Mode option is used to modify the objects in the scene. By entering Edit Mode users can individually select Vertices, Edges, and Faces of an object. o Sculpt Mode is used to modify the objects using brush. When this option is chosen, a red circle is attached along with the cursor that specifies the size of the brush. o Vertex Paint Mode is used to paint vertices of an object using brush. o Weight Paint Mode option is mainly useful in rigging. This mode is similar to Vertex Paint option with the only difference that the weight brush is used in the Weight Paint Mode. 01 Handout 1 *Property of STI  [email protected] Page 7 of 8  AS2209 o Texture Paint Mode is used to edit UV textures and images in 3D Viewport or the UV/Image Editor. References Baechler, O. (2020). Blender 3D by Example (2nd ed.). Birmingham, UK: Packt Publishing. Chandramouli, M. (2022). 3D Modeling and Animation: A Primer. Boca Raton, FL: CRC Press. Tickoo, S. (2018). Blender 2.79 for Digital Artist. Schererville, IN: CADCIM Technologies: 01 Handout 1 *Property of STI  [email protected] Page 8 of 8