3D Renderer (C++)



This is a 3D renderer that I wrote in C++ to load in and display “.md2” files, a fairly old format but a good basis into understanding graphics programming. An “.md2” file merely a list of vertices based around an origin, and a set of 3 integers which is loaded in as a polygon. A polygon contains 3 indexes, each point to a vertex in a list, contained within the model. This means that if a vertex is used more than once, it won’t be duplicated.

The program started off with “Vertex” and “Matrix” classes which held the instructions to multiply them together; this is the basis of transforming and viewing the vertices on the screen. Once we had these, we could implement the full viewing pipeline, using perspective projection. And after this we could visually display these points on screen.

To begin with I focused more on transformations and camera positioning whilst I had the points showing in world space. To visually show the model I made a “DrawWireFrame” method which drew lines between each of the points in the polygon, providing a shape of the object. With this I could test transformations and culling. Backface culling and frustum culling are also included in the program. These used normalisation, dot products and cross products, methods to generate these are included in the “Vertex” class.

Once I had the mathematical stuff down I was able to work on lighting and graphics. I used faceted shading to begin with, which meant I could perfect the lighting, before moving on to gouraud shading. The program features implementation of Ambient, Directional and Point Lights. The lighting is calculated using the Phong Reflection model. I used windows GDI+ graphics library to fill the polygons to begin with, and later on implemented my own “FillPolygon” routine.

Once the lighting was finished, I could work on a better shading option, for this I used Gouraud shading. This stores a colour at each Vertex and then uses interpolation to work out the colours when it fills the triangle. The result makes for a much better model.




 If you would like to see more Images, I have some avaliable on Flickr 

A Standalone Copy is available to try here | 700 KB

If you wanted to see the Soure Code, it is available here | 16 MB

Comments

Post a Comment

Popular posts from this blog

3D Game Engine Using DirectX11 (C++)

Image
This piece of work is what I’m most proud of this semester; it is also one of the projects I had the most fun working on; and because of that, I am currently building upon it and plan to continue over the summer. This is the first time I have ever used a 3D engine, or attempted building my own framework. Framework The engine uses a scene graph to handle the objects in the scene; once the user creates one of the nodes and adds it to the graph, the Initialisation, Updating and Rendering is handled in the underlying framework. I tried to make it so that the user would be able to simply add something to the scene, whilst maintaining as much control as possible. The user is able to create and add a node using 2 lines of code; this then adds the object to the scene graph and everything is handled in the under lying code, the result of this code would load, update and render that object onto the window. The Renderer is what I’ve used as the main DirectX interface...
Read more

MIPS Graphics Library

Image
The reason for this task is twofold: first it helped show me show much work the processor had to do to display a simple shape on the screen; it also taught me memory management. The program was written in MARS virtual environment, and uses the Bitmap display to give a visual representation of the code. Each method uses 4 memory addresses to pass parameters, if any more are needed then they are sent to the stack.  The “SetPixel” method is the simplest, it takes the X, Y and colour of the pixel – calculates it position on the screen and then stores the colour into the memory address into the location where the screen gets its information.  The “DrawLine” method uses Bresenham’s Line algorithm. It takes a start point and end point of the line as parameters, as well as the colour. It then works out the gradient of the line, plots the first pixel, and then adds the gradient again to get to the next pixel. This repeats until it has reached the second point. The “Dr...
Read more