It's time to get moving--using the power of matrices and vectors.
Lab materials must be pushed to your repository one week from now before the next class begins
Read: Labs are designed to be finished in class if you work diligently, but expected to take 1-2 hours outside of class. They are often more 'tutorial' in style, and sometimes the solution may even be provided in pieces for you to type in and experiment. Copying & Pasting is discouraged however--make mistakes, play, and you will further learn the material.
- How many hours did it take you to complete this lab?
- Did you collaborate with any other students/TAs/Professors?
- Did you use any external resources? (Cite them below)
- tbd
- tbd
- (Optional) What was your favorite part of the lab?
- (Optional) How would you improve the lab?
You will be working with some starter code provided. You will be working in the ''BasicWidget.cpp'' and ''Matrix4f.h'' files for this assignment to create a spinning triangle.
The purpose of this lab is to implement and practice using transformations to manipulate a triangle!
Read Sections 1-3: MATRICES IN COMPUTER GRAPHICS
I have found Chapters 3-5 of this video series very beneficial for visualizing what you will be doing with matrix transformations: https://www.youtube.com/watch?v=kYB8IZa5AuE&list=PL_w8oSr1JpVCZ5pKXHKz6PkjGCbPbSBYv&index=4
I found it helpful last lab to include a slidedeck. I will add to this as folks have questions to clear up any confusion.
Lab 4 Slidedeck: https://docs.google.com/presentation/d/1SC_lZk-35d84pY9DZ8fpsqhQZ7K0UxJzYHpSDHVR5IU/edit?usp=sharing
Your task is to implement the following changes in the lab to get a spinning triangle.
In Matrix4f implement the following:
- Transform(Vector4f b)
- InitTranslation(float x, float y, float z)
- InitRotation(float x, float y, float z)
In lab.cpp, perform the following matrix multiplication to rotate the triangle in main.
transform = projection * translation * rotation
Note: The function you have is 'Multiply'
- e.g. projection.Mulitply(translation)
- This performs projection * translation.
- Conceptually you are composing a new matrix by multiplying several matrices together, and setting the final coordinates of a vertex in 2D space (The third dimension is ignored in this lab for now).
Some additional resources to help you through this lab assignment
- learncpp.com - Handy page for learning C++
- cpluscplus.com - Another handy page for learning C++. I particularly like the references as well, which show how to use much of the standard library.
My suggested strategy for this lab is:
- Complete Task 1 first. At a minimum, you need to complete 'Transform(...)' first before a triangle even shows up.
Your solution should compile using the CMake build process.
- Build and execute the ./lab (or ./lab.exe if on windows) and be able to display a spinning triangle that has been translated back 3 units.
What is that, you finished Early? Did you enjoy this lab? Here are some (optional) ways to further this assignment.
- Try creating multiple triangles and spinning them on different axes.
If you found a mistake (big or small, including spelling mistakes) in this lab, kindly send me an e-mail. It is not seen as nitpicky, but appreciated! (Or rather, future generations of students will appreciate it!)
- Fun fact: The famous computer scientist Donald Knuth would pay folks one $2.56 for errors in his published works. [source]
- Unfortunately, there is no monetary reward in this course :)
- Q: None so far!
- A: Hurray! https://www.scratchapixel.com/ (Volume1) is probably a helpful resource.
- Matrix Related