Ray Marching algorithm renderer

Inspired by this article on Habr.

This is my Python 3 implementation of graphical renderer using Ray Marching algorithm.

Requirements and installation

This program requires NumPy package for calculations and PIL for image creating and showing. You can install it with this:

$ pip install Pillow numpy

or this:

$ pip install -r requirements.txt

command.

To run demo, just type:

$ python3 main.py

How it works?

In ray marching algorithm, the whole 3D scene is a signed distance function. So, to define a model, you just need to define f(x, y, z) function, that returns a minimal distance to this model from (X, Y, Z). If this coordinates is inside of a model, distance would be with a minus sign.

For example, sphere definition in Python:

from math import sqrt


def formula(x, y, z, r):
    return sqrt(x**2 + y**2 + z**2) - r

It's simple!

To render this object, you need to instantiate renderer:

renderer = RayMarching(
    width=128,               # Viewport width
    height=128,              # Viewport height
    dist=2.6,                # Distance between (0,0,0) and camera
    iterations=50,           # Number of marching iterations
    sdf=formula)              # Signed Distance Function

And then call render method:

im = renderer.render_to_image()  # PIL.Image
# or
ar = renderer.render_to_array()  # NumPy array, integer is pixel brightness

Feel free to do experiments with it and to contribute to my repo.

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TODO:

• teapot model
• UI, maybe
• multiprocessing for better performance
• ...