raytracer

A raytracer written in OCaml. It can draw planes and spheres with diffuse surface and illuminate them with point & directional light.

Example rendered scene

Dependencies

$ opam install imagelib

Usage

$ make
$ ./main.native

Scene details

You can set camera position, objects & lights in file scene.json. Feel free to look at an example in the repo.

Order of keys at this and lower levels of JSON matters and must be the same as in this specification.

First level must contain three keys: camera, objects, lights.

1. Camera

A list of seven values:

• bottom_left_x : float
• bottom_left_y : float
• upper_right_x : float
• upper_right_y : float
• resolution_x : int
• resolution_y : int
• focal_length : float

Camera is a rectangle on a plane Z=0, looking towards vector (0, 0, 1), i.e. looking towards Z+. You can set positon of this rectangle (its bottom left and upper right corners), resolution and focal length. The latter is the distance between camera and focus (point through which all the rays from pixels go).

2. Objects

A list of JSON objects, each has the following keys:

• type, either sphere or plane
• color, one of the following values: pink, blue, green, gold, seashell, tomato, black, white, orchid, olive
• shader, as for now only diffuse
• data, a list of floats, depending on object type

Data for sphere is a four element list containing:

• position_x : float
• position_y : float
• position_z : float
• radius : float

Data for plane is a six element list containing:

• position_x : float
• position_y : float
• position_z : float
• normal_x : float
• normal_y : float
• normal_z : float

As plane is given by a point and a normal vector to the plane.

3. Lights

A list of JSON objects, each has the following keys:

• type, either point or directional
• data, a four element list of floats, depending on light type

Data for point is a list containing:

• intensity : float
• position_x : float
• position_y : float
• position_z : float

Point light intensity diminishes with distance from the light. It is inversely proportional to the square of the distance from the source.

Data for directional is list containing:

• intensity : float
• direction_x : float
• direction_y : float
• direction_z : float

Directional light behaves like the Sun, i.e. it has constant intensity and its source is given by a direction, not by any particular point.