HW5a – Cantay Caliskan
Blender Game Kit
Chapter 3
Introduction to 3-D and the game engine
In this chapter the author talks about the basics of game graphics, game engines,
and the criteria what makes a good game. Firstly, he makes an overview of the 2-D
graphics saying that in 2-D world there are only two coordinates are required to find a
particular point. In addition to points, lines could also be created. When lines are
connected, polygons are made, which can both be presented in the 2-D and the 3-D world.
In addition to the X and Y coordinates in 2-D world, there is the Z coordinate in 3-D world.
Connecting the lines can also make shapes, such as cube, cone etc. Although using more
polygons creates smoother shapes, it is advisable to use fewer polygons in computer games,
as rendering many polygons can take a lot of time and slow down the game. As it is hard to
create flat shapes with using polygons, Blender offers a set of meshes for usage in creating
other objects. In addition to meshes, Blender also offers material attributes, such as
transparency, color, hardness or how shiny the object should appear. To be able to use as
few polygons as possible, Blender gives the possibility to wrap images around objects with
few polygons, so that they look more realistic. The process of wrapping an image around
round objects is called UV-Mapping. To do this, Blender unwraps the object. It transfers
XYZ coordinates to 2-D world. Blender also offers a set of views: front, sides, top, from
bottom, and behind. Interactive view enables the users to rotate the scene in any direction.
Cameras are used to create an image of the scene. Orthographic and perspective views give
the opportunity to work easily or to have a more realistic view of the scene. To see the
scene, one needs a light, or several lights to make an object have a 3-D appearance. In
games transformations continuously happen, which are rotation, translation, and scaling.
However, transformations are relative, such as in the example of a moving train.
Passengers are not moving relative to each other, however, they are in constant motion
relative to the outside world. Because transformations have an effect on game play, game
designers usually use hierarchies, they parent some objects to the bigger object. Game
engines calculate these transformations. A game engine creates a world, makes calculations
to render images as they change, and uses logic, such as gravity. It also determines the
consequences of an interaction between two objects, such as a collision. Blender’s game
engine requires no programming and utilizes click and drag interface. In true game engines
every object has its own entirety in the scene and makes calculations itself. When it hits an
object it knows how to react likewise the collided object. Fake game engines make
calculations, which determine what an object should do when it is in a particular position.
In addition to game engines, good games are shaped on a successful creation of
components of being funny, realistic, and having an aim. If the creators of a game design a
game, which contains a lot from each of these components, the game is likely to be a hit.
Chapter 4
Blender Basics
In this chapter the author talks about the Blender interface. He says that Blender is
effectively controlled by both mouse and keyboard. Moreover, he talks about some key
buttons for different things that Blender does. Blender gives the user the possibility to
organize the working place as he/she wants. In Blender LMB click selects something and
RMB click deselects it. Pressing the SHIFT key allows the user to select or deselect more
objects, vertices, edges etc. In Blender there are different types of buttons. Some open a
process such as “new” or “delete”, some activate a feature, some change values etc. Menu
buttons open menus and sub contexts. Furthermore, there are different windows, such as
IPO window, 3-D window, Outliner etc. These windows allow the user to design the scene,
to animate it more easily, to wrap an image, to have an overview over the objects, to write a
text, to save the scene… Buttons change one object, add it material, texture, or adds some
logic to the scene. They also help with lighting, shadows, transparency and so on. In
Blender the use can create several scenes in the same file. While creating the scene the user
can copy the former scene, create an empty scene, or link the objects in the former scene to
the new scene. To be able to navigate in scenes, number pad keys are used frequently.
Pressing the SHIFT key allows the user to look from the other side of the particular view.
In 3-D window, the header allows to switch between layers, modes, and views. SHIFT+D
copies an object. ALT+D copies and links the new object to the old one. The link data
menu can be called by pressing CTRL+L. This menu allows the user to link particular
objects to others. G grabs the object, R rotates it, and S scales it. During these operations,
the user can select the center for the process in the header menu. N key calls the number
properties, which give the possibility to enter an exact input for the three transformations
mentioned above. The user can go from the Object Mode to Edit Mode by pressing the
TAB key. In Edit Mode, the user can edit vertices, edges, and faces.
Chapter 27
Game LogicBricks
In this chapter the author talks about the logic behind game making. Game makers
always use sensors in their games. Sensors act like senses. There are different types of
sensors, such as radar, touch, near, and ray. The users can add keyboard sensors, mouse
sensors, touch sensors, collision sensors, radar sensors, near sensors, property sensors,
random sensors, ray sensors, and message sensors. With these sensors the user can give
directions to a particular object, make it move randomly, or make it die after a collision.
With controllers the user can create slightly complex game logic. Actuators are the
executing LogicBricks. There are different actuators, such as motion actuator, constraint
actuator, IPO actuator, camera actuator, sound actuator…With these actuators the user can
add a sound to a game, can make the camera follow a particular object etc. Edit Object
Actuator creates or deletes objects. Scene actuator changes the background images.
Random Actuator makes objects move randomly to create a more realistic game world.
In these chapters, I learned some basic theories of the game making. In addition to
this, I learned how some of the actuators and sensors work, which we haven’t used in class.
I realized that Blender can create fairly complex games. Besides this, I had the chance to
revise what we have learned so far in class, in terms of using Blender and its interface.