Bleeding Visuals

Practical 3

Thursday, October 30, 2008

For this week, we started on doing some real OpenGL.

What I did was making 3D cubes and letting it spin, the cubes were also cel-shaded.

You can download the exe here.(Note: You need visual C++ IDE to run this application.)

Jay
Bleeding Visuals Author

Labels: practical

"freeGLUT and GLUT" in what-is-that-a-day

Sunday, October 26, 2008

what-is-that-a-day in
"freeGLUT and GLUT"

What is GLUT?

The OpenGL Utility Toolkit (GLUT) is a library of utilities for OpenGL programs, which primarily perform system-level I/O with the host operating system. Functions performed include window definition, window control, and monitoring of keyboard and mouse input. Routines for drawing a number of geometric primitives (both in solid and wireframe mode) are also provided, including cubes, spheres, and the Utah teapot. GLUT even has some limited support for creating pop-up menus.

freeglut is an open source alternative to the OpenGL Utility Toolkit (GLUT) library. GLUT (and hence freeglut) allows the user to create and manage windows containing OpenGL contexts on a wide range of platforms and also read the mouse, keyboard and joystick functions. freeglut is intended to be a full replacement for GLUT, and has only a few differences.

What are they and their differences?

freeglut is now very stable and has fewer bugs than the original GLUT. However, there are places where the original GLUT specification did not make clear what order things like callbacks occur and it is possible for application programs that work under GLUT to fail under freeglut because they assume something that GLUT never guaranteed to be true.
New revisions appear periodically - however since it is now quite stable and no new features are planned, these updates are required less and less often. This would change if there was ever a new release of GLUT.

With GLUT, you can create wonders and the game of your dreams.

For more information about GLUT, visit:
http://en.wikipedia.org/wiki/Freeglut
Now you know what is freeGLUT and GLUT.

Jay
Bleeding Visuals Author

Labels: what-is-that-a-day

Practical 2

Friday, October 24, 2008

Question 1 – Define a Callback function?

A callback function is a function that handle events. Callback functions determine exactly what function to call next when an event occurs.

Question 2 - When exactly is myDisplay()called? How do you get to your findings?

myDisplay() is called after glutDisplayFunc(myDisplay) is called as after this line is executed, my screen start to process it's drawing and updating of the graphics on the screen.

Question 3 – List the process to access the VRAM.

Define a struct to represent pixels on the screen.
Define pointer to memory location that will enable pixel plotting.
Based on the screen resolution, a 800x600 memory array is created.
Memory that was created earlier is then transfered into OpenGL’s double buffer.
Buffer will then be cleared to enable a clean surface to work on.
OpenGL’s double buffer will then copy the image onto the VRAM to be displayed on the screen.
Deleting the dynamic array created to prevent memory leak.

Question 4 - What color format are we using here i.e. 8 bits, 16 bits, 24 bits or 32 bits?

24bits. Red, Green and Blue.

Question 5 - How much memory have we allocated?

800*600*3=1.44MB

Question 7 – Describe what has glDrawPixel() done.

glDrawPixels() basically transfers what the buffer had stored into the display to enable the player to see the images. Plot-pixel basically just changes the data of the buffer.

As for what I've done.

I got a code to draw a circle, basically I have used point distance from the origin to determine where to plot the pixels.

Jay
Bleeding Visuals Author

Labels: practical

Lecture answer.

Wednesday, October 22, 2008

During the computer graphics lecture today, the lecturer posted two questions.

Question 1
I want my game to run at 800 x 600 on 32 bits. How much VRAM do I need?

Answer 1
800 x 600 x 4 byte = 1920 000 bytes around 1.83 megabytes
(Note: 1 megabytes=1024*1 megabytes=1024 kilobytes, 1 kilobytes=1024*1 kilobytes=1024 bytes)

Question 2
My artist are told they have a maximum of 32MB to use for textures. How many textures can they use if they are limited to 256 x 256, with a 24 bits palette of 8 bits colour depth?

Answer 2
Total memory allocated = 32 megabytes x 1024 x 1024 = 33554432 bytes
Memory taken per texture = 256 x 256 x 1 byte + (256 x 3) = 66304 bytes

Possible images allowed = 33556632/66304
= 506.0694981
roughly = 506 images.

Ok, I know alot of you got the answer 512 images, but take note that each images had a palette. In this case, the palette is a 24 bits palette which account to an additional of 768 bytes of memory assign to each texture. That explains the answer.

I hope this clears up the ponder of the question. For more information, take a look at this article: http://en.wikipedia.org/wiki/Palette_(computing)#Related_terms_and_technologies

Jay
Bleeding Visuals Author

Labels: lecture

Sharing

Monday, October 20, 2008

Hours of surfing through video sharing site YouTube, I came across this interesting clip. Apparently someone made a stop motion of popstar Britney Spears's Stronger music video.

Don't think this is computer graphics related, well just enjoy.

Jay

Bleeding Visuals Author

Labels: stop motion stronger britney spears

Game Review "Legend of Zelda : The Wind Waker"

Friday, October 17, 2008

From the breath-taking visuals to the vivid coloured filled environment. Legend of Zelda : The Wind Waker is a game you certainly cannot afford to miss.
Review

Title:	Legend of Zelda : The Wind Waker
Platform:	Nintendo Gamecube
Released:	Mar 24, 2003
Genre:	Fantasy Action Adventure
Developer:	Nintendo

The Legend of Zelda: Wind Waker is a major breakthrough from its predecessors in terms of its graphics. The game implemented cel-shading drawing technique to give this entry of the series a graphical boost.

You play again as a young boy living in peace on an island with your grandma and sister. After your younger sister Aryll is held captive, you’ll meet a group of pirates and the adventure begins. The captain of the crew is Tetra, the alter form of Princess Zelda in this series. After a series of event, Tetra is the one that is held captive. And the real game starts from here.

In terms of its game play, Legend of Zelda is a fun and engaging. The story forces the player to explore the world and discover its hidden secrets. You pretty much travels around in your boat called the Red Sea Lion on the great sea during the course of this game.

In terms of graphics, it's stunning. From the very first time glance at your television screen, you will feel it is different from the other games. The game was made cel-shaded, a technique where hard shadows and deep contrast that make the game feel cartoony. Each character in the game is unique and colourful. The models in the game are detailed and crisp with a stunning environment, you pretty much got yourself into a children's colouring book.

With good visuals, accompanying music need to be up to standard to pair with it. Fortunately the scores have done it well. The sounds are engaging and exciting. Sounds in the game ranged widely from the deep and quiet caves to the loud and buzzing town. The sound designer really puts a lot of effect in matching actions and the ambient well with the game play.

Well, the nature of the game is still an RPG, it might not score as well in replay but hardcore fans will sure to enjoy the game no matter how many run given that the varied environment make sure the player have plenty of places to explore besides the places that main quest will lead to. Still to a casual player, the game might be just a one shot play that will leave the disk at a corner to collect dusk.

Overall, this game is a must have. Its stunning visuals already differentiate itself from the other Zelda games. Despite the cartoony visuals aiming at a younger audience, playing the game at least once will guarantee a visual treat for all ages.

Labels: review

"Computer Graphics" in what-is-that-a-day

what-is-that-a-day in
"Computer Graphics"

What are computer graphics(CG)? CG are actually visual representation of manipulating pictorial data to the user. CG can be found nearly anywhere in the world today.

CG filled in the void where the world wouldn't be able to offer visually.

Windows Vista from Microsoft

Today computers and computer-generated images touch many aspects of our daily life. CG can construct visual representation of statistics to a form such that it is easier to understand.

A wide array of tools were also created to manipulate computer imagery.

(Left) Gizmodo.com (Middle) Half Life 2: Lost Coast from Valve (Right) AutoCAD from Autodesk

Computer graphics not only change the way the world looks. It changed the way artist express their creativity. It bought a whole new level of expression and possibilities. Art no longer limit itself to just brush and paint, mathematical formula works terrific too. like vector arts.