raytracing-render

Developing ray tracing render from scratch.

Key Features

• Using k-d tree for fast traversal of 3D scene objects
• Using Surface Area Heuristic for building optimal k-d tree
• Rendering entire scene in parallel (using OpenMP)
• Texture mapping (using libpng)
• Saving rendered image to file (using libpng)
• Loading 3D models from *.obj format
• Phong shading
• Phong reflection model
• Two types of primitives: triangle and sphere
• Reflections, shadows, fog effect, multiple light sources

Requirements

Requires libpng to be installed.
Tested on Mac OS 10.8 with gcc 4.2 and gcc 4.7.

Demo with GLUT front-end

All rendering routines are performing by this render, not OpenGL. Just using GLUT to display rendered image.

make run_demo_gl

• Use controls ← ↑ → ↓ to rotate camera
• Use CTRL + ↑ or CTRL + ↓ to move camera forward or backward
• Use SHIFT + ↑ or SHIFT + ↓ to move camera up or down
• Use SHIFT + ← or SHIFT + → to move camera left or right
• Use ALT + ↑ or ALT + ↓ to change focus of camera
• Use ESC to exit

Create demo from scratch

Lets create example application from scratch :) You will get following image:

#include<stdio.h>#include<canvas.h>#include<render.h>#include<obj_loader.h>#defineCANVAS_W 400
#defineCANVAS_H 400
// Boost by rendering in parallel#defineTHREADS_NUM 4
#defineBACKGROUND_COLOR rgb(255, 255, 255)
#defineMAX_OBJECTS_NUMBER 10000
#defineMAX_LIGHT_SOURCES_NUMBER 5
intmain(void) {
// Allocating sceneScene*scene=new_scene(MAX_OBJECTS_NUMBER,
MAX_LIGHT_SOURCES_NUMBER,
BACKGROUND_COLOR);
// Allocating new sphereFloatradius=100;
Point3dcenter=point3d(0, 0, 0);
Colorsphere_color=rgb(250, 30, 30);
Materialsphere_material=material(1, 5, 5, 10, 0, 10);
Object3d*sphere=new_sphere(center,
radius,
sphere_color,
sphere_material);
// Adding sphere to the sceneadd_object(scene,
sphere);
// Allocating new triangleObject3d*triangle=new_triangle(point3d(-700, -700, -130), // vertex 1point3d( 700, -700, -130), // vertex 2point3d( 0, 400, -130), // vertex 3rgb(100, 255, 30), // colormaterial(1, 6, 0, 2, 0, 0) // surface params
);
// Adding triangle to the sceneadd_object(scene,
triangle);
// Loading 3D model of cow from *.obj file// defining transformations and parameters of 3D model// TODO: must be refactored...SceneFaceHandlerParamsload_params=new_scene_face_handler_params(scene,
// scale:40,
// move dx, dy, dz:-150, -100, 30,
// rotate around axises x, y, z:0, 0, 0,
// colorrgb(200, 200, 50),
// surface paramsmaterial(2, 3, 0, 0, 0, 0)
);
load_obj("./demo/models/cow.obj",
// default handler which adding polygons of 3D model to scene:scene_face_handler,
&load_params);
// This function is requried (bulding k-d tree of entire scene)prepare_scene(scene);
printf("\nNumber of polygons: %i\n", scene->last_object_index+1);
// Allocating new light sourceColorlight_source_color=rgb(255, 255, 255);
Point3dlight_source_location=point3d(-300, 300, 300);
LightSource3d*light_source=new_light_source(light_source_location,
light_source_color);
// Adding light source to the sceneadd_light_source(scene,
light_source);
// Adding fogFloatdensity=0.002;
set_exponential_fog(scene, density);
// Allocating camera// TODO: It's a pity, but quaternions are not implemented yet :(Point3dcamera_location=point3d(0, 500, 0);
Floatfocus=320;
Floatx_angle=-1.57;
Floaty_angle=0;
Floatz_angle=3.14;
Camera*camera=new_camera(camera_location,
x_angle,
y_angle,
z_angle,
focus);
// Rotate camera if needed// rotate_camera(camera, d_x_angle, d_y_angle, d_z_angle);// Move camera if needed// move_camera(camera, vector3df(d_x, d_y, d_z));// Alocate new canvas, to render scene on itCanvas*canvas=new_canvas(CANVAS_W,
CANVAS_H);
render_scene(scene,
camera,
canvas,
THREADS_NUM);
// Saving rendered image in PNG formatwrite_png("example.png",
canvas);
release_canvas(canvas);
release_scene(scene);
release_camera(camera);
return0;
}

Launch it

make example && ./example

Average number of intersections per pixel

Define different values of maximal depth of Kd-tree and track average number of ray intersections per pixel:

make DEF="-DRAY_INTERSECTIONS_STAT -DMAX_TREE_DEPTH=25" run_demo_gl

make DEF="-DRAY_INTERSECTIONS_STAT -DMAX_TREE_DEPTH=25" example && ./example

Benchamrks

Illustration of kd-tree boosting:

1. Without kd-tree, and without bounding box:

make clean > /dev/null
make DEF="-DRAY_INTERSECTIONS_STAT -DNO_BOUNDING_BOX -DMAX_TREE_DEPTH=0" benchmark > /dev/null &&
./benchmark
make clean > /dev/null

2. Without kd-tree, but with bounding box:

make clean > /dev/null
make DEF="-DRAY_INTERSECTIONS_STAT -DMAX_TREE_DEPTH=0" benchmark > /dev/null &&
./benchmark
make clean > /dev/null

3. With kd-tree, but without bounding box:

make clean > /dev/null
make DEF="-DRAY_INTERSECTIONS_STAT -DNO_BOUNDING_BOX -DMAX_TREE_DEPTH=20" benchmark > /dev/null &&
./benchmark
make clean > /dev/null

4. With id-tree, and with bounding box:

make clean > /dev/null
make DEF="-DRAY_INTERSECTIONS_STAT -DMAX_TREE_DEPTH=20" benchmark > /dev/null &&
./benchmark
make clean > /dev/null