My tinyrender

My simple implementation of rendering based on this course (btw the course is great). Unlike it is instructed in the course, I wrote the code in python. I used numpy to make it faster.

The goal of this project is to learn how to render an object (given in obj format).

Structure:

• lessons1-6.ipynb - prototyping first steps (the code here is a real mess)
• my_render/ - at some point I brushed up the code a bit and made it more structed. So here is more structed version with shader abstraction
• obj/ - .obj .png files of 3d models

Here is my progress:

1. First of all we need to know how to render simple primitives like a line, (filled) triangle:

2. After parsing obj file and applying the methods above we have:

Knowing a triangle normal and light directions we can get this (intensity ~ n*l):

Yet there is smth wrong with the mouth.

3. Introducing z-buffer solves the issue:

Changing the gray color on the known texture gives us this:

(wow!)

4. The next step is to take into account that we take an image from a camera view. So we need to implement perspective projections:

5. While rendering the colored triangles we used barycentric coordinates (to understand if a point is inside a triangle). And here it helps us again: knowing color (or anything else) of triangle vertices we can interpolate it all over the triangle (using the barycentric coordinates):

6. Adding normal and specularity maps. Minor modifications of shader leads to the following results.

TODO list:

• Bresenham’s Line Drawing Algorithm
• Triangle rasterization and back face culling
• Hidden faces removal (z buffer)
• Perspective projection
• Moving the camera
• Shaders for the software renderer
• Shadow mapping
• Ambient occlusion