CSE410 Assignment 1- OpenGL Solution

There are three tasks in this assignment.
1. Fully Controllable Camera (Problem 1.exe)
2. Gun (Problem 1.exe)
3. Bubbles (Problem 2.exe)

Fully Controllable Camera (Problem 1.exe)
Up arrow - move forward
Down arrow - move backward
Right arrow - move right
Left arrow - move left
PgUp - move up
PgDn - move down
1 - rotate/look left
2 - rotate/look right
3 - look up
4 - look down
5 - tilt clockwise
6 - tilt counterclockwise

Hint:
Maintain four global variables: one 3d point 𝑝𝑜𝑠 to indicate the position of the camera and three 3d unit vectors 𝑢, 𝑟, 𝑎𝑛𝑑 𝑙 to indicate the up, right, and look directions respectively. 𝑢, 𝑟, 𝑎𝑛𝑑 𝑙 must be perpendicular to each other, i.e.,
𝑢. 𝑟 = 𝑟. 𝑙 = 𝑙. 𝑢 = 0, 𝑢 = 𝑟 × 𝑙, 𝑙 = 𝑢 × 𝑟, 𝑟 = 𝑙 × 𝑢.

You should initialize and maintain the values of 𝑢, 𝑟, 𝑎𝑛𝑑 𝑙 such that the above property holds throughout the run of the program. For example, you can initialize them as follows:
𝑢 ,
𝑝𝑜𝑠 = (100, 100,0)

And while changing 𝑢, 𝑟, 𝑎𝑛𝑑 𝑙, make sure that they remain unit vectors perpendicular to each other.

The first 6 operations listed above are move operations, where the position of the camera changes but the up, right, and look directions do not. The last 6 operations are rotate operations, where the camera position does not change, but the direction vectors do.

In case of a move operation, move 𝑝𝑜𝑠 a certain amount along the appropriate direction, but leave the direction vectors unchanged. For example, in the move right operation, move pos along r by 2 (or by any amount you find appropriate) units. In case of a rotate operation, rotate two appropriate direction vectors a certain amount around the other direction vector, but leave the position of the camera unchanged. For example, in the look up operation, rotate 𝑙 𝑎𝑛𝑑 𝑢 counterclockwise with respect to r by 3 (or by any amount you find appropriate) degrees.

If you maintain 𝑝𝑜𝑠, 𝑢, 𝑟, 𝑎𝑛𝑑 𝑙 in this way, your gluLookAt statement will look as follows:
gluLookAt(pos.x, pos.y, pos.z, pos.x + l.x, pos.y + l.y, pos.z + l.z, u.x, u.y, u.z);


Gun (Problem 1.exe)
Color pattern of the gun should be same as the one modeled in Problem 1.exe. You can’t use any OpenGL library function to draw the parts of the gun.

Press the keys q, w, e, r, a, s, d and f to find out how the gun rotates. Also observe that after certain amount, each joint ceases to rotate.

Left click the mouse to fire the gun.


Right click the mouse to toggle viewing the axis.













Bubbles (Problem 2.exe)
The camera is fixed looking at the center of the green boundary square from a perpendicular position. There is red circle inside the square.

After the program starts, five bubbles will pop up one by one from the left bottom region of the square and start moving towards a random direction. None of the bubbles will go out of the boundary square. Rather, they will be reflected upon colliding with the boundary of the square. Note that, the bubbles that haven’t yet gone inside the red circle will cross one another.

When a bubble goes completely inside the red circle, it will never go out of the circle. Rather, it will reflect upon colliding with the circle. It will also reflect with other bubbles that are completely inside the red circle. Note that, the bubble will not reflect with bubbles that are outside the red circle even partially.

The program will also support the following functionalities.
Up arrow – increase the speed of the bubbles
Down arrow – decrease the speed of the bubbles
Press ‘p’ – resume/pause the movement of the bubbles

There should be an upper and lower bound for the speed of the bubbles so that the speed can’t be increased to ∞ and decreased to 0.

The length of the square and the radius of the circle and bubbles are not strictly specified. Adjust the values in order to reproduce the given figure as close as possible.
The bubbles have the same velocity.


Hint:
Maintain two global variables for each bubble to indicate its position and speed.


Check whether a bubble comes completely inside the circle. It can be done by calculating the distance between the centers of the bubble and the red circle. The bubble is inside the circle if the distance is ≤ radius of the circle – radius of the bubble.

You have to reflect bubbles with respect to one another and also with respect to the red circle. You can follow this to find the formula. Please try to understand anything before applying in the assignment.

Submission Guideline