3D-engine

Work with this repository

To clone this repository on your local computer please run:

$ git clone https://github.com/PierreGuilmin/3D-engine.git

This project was written under C++ (C++11). It uses the open-source library SFML (SFML 2.5.0) which is a cross-platform library written in C++ to open window, draw 2d lines/images, handle the keyboard and the mouse... The easiest way to install it on a mac is by using the (famous) 🍺 Homebrew package manager:

$ brew install sfml

Otherwise the library can be compiled from source on the SFML website under the Download section.

The default compilater used in the makefile is clang++. Running the following command in the project folder will compile the sources and create an executable called 3D-engine:

$ make

To clean the project .o and .d located in /obj and remove the executable you can run in the project folder:

$ make clean

If you don't have clang++ you can compile the project with any another compiler (g++ for example), by modifying the two first lines of the makefile to match your compiler:

# current makefile first lines
CXX      = clang++ # compiler name
CXXFLAGS = -Weverything -Wno-c++11-extensions -Wno-padded -Wno-c++98-compat -Wno-float-conversion -Wno-conversion -std=c++11 # compiler flags

# change for something like
CXX      = g++
CXXFLAGS = -Wall -Wno-c++11-extensions

What is the project about

This is a project I did on my own during my free time because I was curious about 3D rendering and wanted to practice C++. The goal was to render 3D objects on my computer screen without using any 3D libraries like OpenGL, doing every projections from the 3D space to the 2D screen on my own, as well as handling the camera rotation and objects movements.

⚠️ Because I just created this repository the project is still not well commented.

See under a view of the basic scene proposed in main.cpp (the application is on the right, the left pannel is a terminal instance):

The commands

The commands to move in the 3D space are really intuitive and shouln't cause problem:

• Move your mouse to see around
• Use [W, A, S, D] to go [front, left, back, right] (front and back are going in the direction where your mouse points)
• Use [Q, E] to go [up, down]

The architecture

The following files implements basic helpers class and functions:

• mouse.hpp and mouse.cpp: facilitate the access to the mouse last movement
• general.hpp and general.cpp: various small tool functions and classes

The following files are the heart of the engine:

• vector3d.hpp and vector3d.cpp: implements the Vector3d class that represents a vector in a 3D space
• geometry.hpp and geometry.cpp: implements the Segment3d, Plane3d, Solid3d and Camera classes

The main.cpp setup the window, create the objects and handle the event and the display in the main loop of the program.
Notice how easy it is to create and render:

• a cube of size 50 centered in (0, 0, 0):

  // → at the beginning of the main
  // create the cube, the string argument specifies the cube size: 50
  Solid3d cube(Solid3d::SOLID_TYPE::CUBE, "50");
  // set the cube position in a cartesian 3D coordinate system
  cube.set_center(Vector3d(-50, -50, -50));
  
  // → in the main loop
  // render the cube on the given window with the given camera view
  cube.render_solid(window, camera);

• the white rotating sphere on the image:

  // → at the beginning of the main
  // create the sphere, the string argument specifies:
  //   - the sphere size: 40
  //   - the number of circle: 20
  //   - the number of points per circle: 50
  // so this sphere is made of 20 x 50 = 1,000 points
  Solid3d rotating_sphere(Solid3d::SOLID_TYPE::SPHERE, "40:20:50");
  // set the sphere position in a cartesian 3D coordinate system
  rotating_sphere.set_center(Vector3d(60, 0, 0));
  
  // → in the main loop
  // rotate sphere around the given axis, proper to the object (because we set object_axis = true), by 3 degrees every loop
  rotating_sphere.rotate(Vector3d(), Vector3d(1, 1, 0), 3, true);
  // render the sphere on the given window with the given camera view
  rotating_sphere.render_solid(window, camera);