[SOLVED] Cs33400/ece30834 assignment #1 – project it! p0

City Roaming (Camera Transformation)
Objective
The objective of this assignment is helping you understand matrix transformations, coordinate systems in OpenGL and camera projection mechanisms. In this assignment we provide you a tiny city to walk in and you should be able to reach every corner of this city after correct implementation. After working on this assignment, you will learn to use linear algebra to transform the coordinates from one space to another coordinate space, and apply matrix operations to cameras for an interactive application.

(a) Ground Camera (b) Overhead Camera
Summary
The assignment is to implement an interactive city roaming program. The program includes a lowpoly city model[1]. There are also two cameras that can be switched at any time: a ground camera and an overhead camera. The ground camera simulates the view of a person walking in the city. The overhead camera gives you a complete view of the whole scene and it supports the trackball feature (you can use the mouse dragging to rotate the scene around its center).
CS33400/ECE30834 Assignment #1 – Project it!

Your first task is to compute the viewing transformation of the camera. Then you have to implement the function for rotation, and use rotation & translation functions to support the transformations of the camera, including moving forward/backward and turning left/right. Another feature is part of the trackball feature, where you will implement the scroll wheel operation, so that the camera can be moved closer to/farther from the scene.
Specifics
1. Start with the template from the course website.
2. Compile and run the template.
Since the model is large, it will take some time to load. The figures above show what you will see when running the template (left: ground view; right: overhead view; you can press “s” to switch). The two camera instances cam ground and cam overhead are kept by class GLState.
Read the code to understand how it works, and then make the changes below.
3. View Transformation.
In OpenGL, a view matrix transforms the world coordinates to the view space. The function Camera::updateViewProj updates the 4×4 matrices Camera::view and Camera::proj constantly so the camera views can also be updated. Initially, in the function updateViewProj, we are using glm::lookAt to calculate the view matrix. Delete it before starting your implementation. We are using the function Camera::calCameraMat to replace glm::lookAt. Here in calCameraMat, you need to construct the view matrix using eye, center, and up vectors. In this function, utility functions are provided to compute normalization, cross/dot product, and transpose (you can also use corresponding glm functions).
4. Rotation.
Implement your own version for computing the rotation matrix in Camera::rotate. Convert degrees to radians. Condition the result on three cases (rotate around x/y/z axis).
5. Turning Left/Right.
In the ground view, the camera should be able to turn left or right. Implement this in
Camera::turnLeft and Camera::turnRight. Use Camera::rotate (implemented in the previous step) for this task. Use Camera::rotStep as the rotation speed (how much to rotate between two frames).
6. Moving Forward/Backward.
In the ground view, the camera should be able to move around. Implement this in
Camera::moveForward and Camera::moveBackward. Use the provided Camera::translate. Use Camera::moveStep as the movement speed.
7. Scroll Wheel Interactions.
In the overhead view, scrolling the mouse wheel should move the camera closer to or farther from the scene. Implement this in the function GLState::offsetCamera. Update the coordinates of the overhead camera (cam overhead). Set two cut-offs to prevent the camera from being pushed too close or too far away. If you don’t have a scroll wheel, use I to zoom in and O to zoom out.
CS33400/ECE30834 Assignment #1 – Project it!

8. Supported Operations.
After implementing the above, your program should support the following operations:
• Mouse Controls (only in overhead view):
– Left click + drag to rotate the camera.
– Scroll wheel(I+O) to zoom in/out.
• Keyboard Controls (only in ground view):
– A: Turn left.
– D: Turn right.
– W: Move forward.
– X: Move backward.
– Z: Move down.
– C: Move up.
– S: Switch between the two cameras.
9. Debugging Functions.
Use the provided functions to debug your implementation: Scene::printMat3,
Scene::printMat4, Scene::printVec3, Scene::printMat4
10. Notes
You are NOT allowed to use glm::lookAt, glm::scale, glm::rotate, glm::translate anywhere in your code.
The code lines requiring your implementation are marked “TODO”; under each TODO. there are more detailed instructions guiding you through the tasks. However, depending on your particular implementation there might be other places for you to change code. You are expected to add/modify the code as necessary to make sure the application runs smoothly.
Turn-in Instructions
Don’t wait until the last moment to hand in the assignment!
For grading, the program will be compiled on Linux and run from the terminal (with Visual Studio as a fallback – please try to avoid platform-specific code (e.g., don’t #include <windows.h>)), run without command line arguments, and the code will be inspected. If the program does not compile, zero points will be given.
Good luck!
[1] The model is taken from