Graphics

Introductory Notes!

• The Utah Teapot is a 3D model; because of its shape, it was and is often used to test different properties or settings of graphics engines.
• From Wikipedia: "Rendering is the process of generating an image from a 2D or 3D model (or models in what collectively could be called a scene file), by means of computer programs."
• In 3D, models and meshes are colored in by textures and have their appearances changed by other effects like lighting.
• For more complex transformations in modelling, matrices are used to modify different points' coordinates. Simple translations are just addition or subtraction, but it can be taken further with multiplication by other matrices or special matrices.

Alice

Like Scratch, Alice uses drag-and-drop code blocks. Unlike Scratch, though, it revolves around a 3D world, a mobile camera, and classes in its structure.

In this, the first couple of frames are actually of the blender turning; every time the "d" key is pressed, the blender turns right by about 20 degrees. Using WASD, it's got the ability to go forwards, backwards, and turn side to side.

In addition to the previous, the camera stays aligned with the blender because the camera's vehicle is the blender; it's fixed in relation to the blender.

Next is the shooting sequence. "Projectile" is the cookie I used as a bullet; it normally stays hidden, but when space is pressed, it changes its point of view (both position and orientation) to the blender's, shows itself, and sends itself careening. The blender itself has multiple parts; the lid moves up and down in relation to the blender because it's also using the blender as a vehicle.

SketchUp

SketchUp isn't a programming language but a modelling tool; using different plane shapes, lines, and other geometric figures, you can create a 3D model of whatever you want.

There're a couple of different tool types here:

• Figure tools: These manipulate plain (or plane) shapes into whatever you need; just click once to start drawing, and click again to end for most. These include figures like rectangles and circles and strokes like lines and arcs.
• Typographic tools: Literally expanding on the figures created before, these usually give a third dimension or a different depth to any closed shape, even able to segment already-deepened shapes. Also, basic polygonal properties like orientation and size can be easily changed with these.
• Construction tools: While I don't really know how to use most of these well enough, these help to geometrically construct your model to computational precision. The most generally useful of these is the measuring tape, which adds reference lines to the model that can interact with figure and depth placement.

The first one I made is on the right; I was able to subdivide the larger figure into smaller planes that could each be colored accurately. After, I copied that one to make a textured one; where the parts were differently colored, I raised or lowered the plane relative to the rest to show the difference between surfaces. The main problem was that both the arms and legs were classified as components before; any changes made to one would transfer over to the other three. I had to turn the original's into unique groups separate from the textured one to restore them.

Another day, another model; this one's a spaceship of some sort.

Again, the only real advanced technique I used was to have components; anything that could be symmetrical was added to a single component that flipped it to the other side.

Another hour of nothing, another model; I manipulated the textured model into a pose by manipulating each body part's group and splitting up limbs to make joints.

VPython

Using Python's normal programming structure, VPython adds in a world display and different figures to use and play around with. To start off, here's the intro exercise:

So, what exactly is going on?

1. Using VPython's library (in an earlier line, we do "from visual import *"), we could use the sphere function to draw a sphere with certain attributes. The first line is a scoop of strawberry.
2. Using more sphere attributes, we made a white vanilla scoop that's had its y position raised above the previous. (Not entering a position just sets it to the origin.)
3. Lastly, the cone's got a hecka lot of stuff: it's positioned at negative 0.5 y, it's got specific dimensions, it's oriented by an axis going downwards, it's hued orange, and it's textured with a wood texture.

I made the obligatory shooting game in this; however, Python's limitations as a language hinders any sort of pacing in an action game:

• Easy-to-use keyboard event listeners have to put the program on hold to wait for a press; the program only updates once per keypress. (In the animation, every frame is one keypress.)
• Of the keyboard event listeners (raw_input and VPython's scene.kb.getkey()), both have their own problems: raw_input requires both the command prompt and having to constantly return the input, and the keygrabber from VPython is laggy when changing input from one key to another.
• As far as I know, there isn't any sort of easy movement like steps in Scratch that changes based on direction; vectors can only go so far, and are mostly reliant on coordinates still.

...Although it is pretty fun to draw with...

At any rate, here's the code from it:

Here're the assigned projects, though:

For this, we had a constantly increasing time variable (t). Tapping into sine and cosine, we made the x and z coords trig functions, and I messed with the amplitude for an elliptical orbit.

I didn't spend as much time on this one; the main concept is that the ball's elevated position is constantly lowered by gravity for a negative velocity. When it hits the bottom, the negative velocity is reversed until it's overcome and arcs back down.

Pretty much just a wireframe with cylinders, every edge is bound to a frame in order to rotate correctly. Also, every cylinder is placed to be centered relative to the origin