ozoneguy / 3gc3-project

Final project for Computer graphics course

Instructions

Installation

You will require to install freeimg library.

Freeimg installation instructions

• Linus
  • sudo apt-get install libfreeimage3 libfreeimage-dev
  • sudo pacman -S freeimage
• Mac OSX
  1. Use homebrew
  2. brew install freeimage

Compiling and running the program

Use make to compile the program or make run to compile and run. Must be used in the same location as this README.

Known issues

• The model scales are horrible

• There are some issues with the collision resolving algorithm due to floating point arithmetic.

  The algorithm cannot properly calculate the norm or fully exit the colliding object within a factor of 10^-2.

• The textures do not render

Controls

• Movement is done thought conventional W A S D controls
• SPC is used for jumping
• Mouse is used to look around
• is used to bring the colour menu. Colour is set depending on where the mouse is on the screen when the button is released.
  • Some platforms and work objects are visible and intractable only when you current colour is the same as their colour
  • The available colours are RED, BLUE, and GREEN.
• is used to pause the game.

Class Diagram

• Update UML diagram

NOTE: Some aspects of this diagram differ from the actual implementation.

Collision

AABBs

For collision we are using AABBs(Axis Aligned Bounding Box). They are simply a rectangle, cuboid in 3D, that totally encompasses the colliding object while being very quick to check collisions for. They are supposed to serve as initial collision detection followed by more complex collision detection algorithm, if the AABBs do collide. In our implementation, we are only using AABBs as we do not have an algorithm to check vertex/model level collision.

The base class AABB serves as the common implementation of all physics objects in the project.

It also directly inherited by the Platform class, as they are static physics object.

Moving AABB

Very similar to AABB, but they also have velocity and an update function. The update serves to update the state of the MovingAABB. This is inherited by all entities. They can also be used by moving platforms, when those are implemented.

AABB Tree and branches

An AABB tree serves as an efficient implementation for collision detection between all AABB objects in the world, a balanced binary tree. A tree consists of a single AABBBranch which consists of two AABB objects, these AABB objects can be any type of AABB, including an AABBBranch.

The top branch is the tree. The branch serves to update the AABBs in the tree, delete, add, and detect collision with other AABB objects; not with AABBBranch objects.

A note about use of AABBs

For more complex models, it is possible to have multiple AABBs. Essentially, and object would be represented by an AABB tree which doesn't detect internal collision. For example, the player would have an AABB between each joint.

This could be done in two different ways. The first is to manually create the AABB tree for each complex model.

The second is when exporting the obj model to export it in groups. Each group will end up having its own AABB inside of the entity AABB tree. This would be the better implantation as it will allow for more accurate collision detection while only utilising AABBs, or some variant that can rotate.

Model and obj files

A model class handles all model related operations. It responsible for loading the obj model and returning the relevant details to create an encompassing AABB. It is a field in all classes which should have a 3D representation in the world.

Camera

The camera is part of the player class. It uses the player's position and rotation to place itself in the world and look in the correct direction. The header for the camera has some constants which allows us to offset the position and rotation of the camera for a better experience.

Developers

• Omar Alkersh
• Youssef Mikhail