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

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