Console for photon mapping in python (#5)

* PM Python can be loaded w params

* Update README.md
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Jakub Poćwiardowski 2025-01-19 14:26:03 +01:00 committed by GitHub
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@ -43,3 +43,8 @@ python main.py --algorithm ray_tracing
# Wywołanie algorytmu ray tracing ze specyfikacją sceny z folderu scenes, liczbą sampli na pixek, rozdzielczością, środowiskiem i rozmyciem środowiska
python main.py --scene three_spheres --samples_per_pixel 100 --resolution 100x100 --environment lake.png --env_blur 10
```
```bash
# Wywołanie algorytmu photon mapping ze specyfikacją liczby fotonów i maksymalnej głębokości
python main.py --algorithm photon_mapping --max_depth --num_photons 1000
```

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@ -1,221 +0,0 @@
import numpy as np
import matplotlib.pyplot as plt
# Define basic vector operations
class Vector3:
def __init__(self, x, y, z):
self.x = x
self.y = y
self.z = z
def __add__(self, other):
return Vector3(self.x+other.x, self.y+other.y, self.z+other.z)
def __sub__(self, other):
return Vector3(self.x-other.x, self.y-other.y, self.z-other.z)
def __mul__(self, scalar):
return Vector3(self.x*scalar, self.y*scalar, self.z*scalar)
def dot(self, other):
return self.x*other.x + self.y*other.y + self.z*other.z
def norm(self):
return np.sqrt(self.dot(self))
def normalize(self):
n = self.norm()
return Vector3(self.x/n, self.y/n, self.z/n)
# Define the photon
class Photon:
def __init__(self, position, direction, power):
self.position = position
self.direction = direction
self.power = power
# Define a simple sphere
class Sphere:
def __init__(self, center, radius, color):
self.center = center
self.radius = radius
self.color = color
def intersect(self, ray_origin, ray_direction):
# Solve quadratic equation for intersection
oc = ray_origin - self.center
a = ray_direction.dot(ray_direction)
b = 2.0 * oc.dot(ray_direction)
c = oc.dot(oc) - self.radius*self.radius
discriminant = b*b - 4*a*c
if discriminant < 0:
return None # No intersection
else:
t = (-b - np.sqrt(discriminant)) / (2.0*a)
if t < 0:
t = (-b + np.sqrt(discriminant)) / (2.0*a)
if t < 0:
return None
hit_point = ray_origin + ray_direction * t
normal = (hit_point - self.center).normalize()
return (t, hit_point, normal)
# Define a simple plane
class Plane:
def __init__(self, point, normal, color):
self.point = point
self.normal = normal.normalize()
self.color = color
def intersect(self, ray_origin, ray_direction):
denom = self.normal.dot(ray_direction)
if abs(denom) > 1e-6:
t = (self.point - ray_origin).dot(self.normal) / denom
if t >= 0:
hit_point = ray_origin + ray_direction * t
return (t, hit_point, self.normal)
return None
# Scene setup
sphere = Sphere(Vector3(0, 0, -5), 1.0, np.array([1, 0, 0])) # Red sphere
plane = Plane(Vector3(0, -1, 0), Vector3(0, 1, 0), np.array([0.5, 0.5, 0.5])) # Gray plane
objects = [sphere, plane]
# Light source
light_position = Vector3(-5, 5, -5)
light_power = np.array([1, 1, 1]) * 1000 # Intense white light
# Photon map
photon_map = []
# Parameters
num_photons = 10000 # Number of photons to emit
max_depth = 5 # Maximum number of bounces
gather_radius = 0.5 # Radius for radiance estimation
def emit_photons():
for _ in range(num_photons):
# Emit photons in random directions from the light source
direction = random_unit_vector()
power = light_power / num_photons
photon = Photon(light_position, direction, power)
trace_photon(photon, 0)
def trace_photon(photon, depth):
if depth > max_depth:
return
closest_t = np.inf
hit_object = None
hit_info = None
# Find the nearest intersection
for obj in objects:
result = obj.intersect(photon.position, photon.direction)
if result:
t, hit_point, normal = result
if t < closest_t:
closest_t = t
hit_object = obj
hit_info = (hit_point, normal)
if hit_object:
hit_point, normal = hit_info
photon_map.append((hit_point, photon.power))
# Diffuse reflection
new_direction = random_hemisphere_direction(normal)
photon.position = hit_point
photon.direction = new_direction
# Absorb some power
photon.power = photon.power * 0.8 # Simple absorption
trace_photon(photon, depth+1)
def random_unit_vector():
theta = np.random.uniform(0, 2*np.pi)
z = np.random.uniform(-1, 1)
r = np.sqrt(1 - z*z)
return Vector3(r * np.cos(theta), r * np.sin(theta), z)
def random_hemisphere_direction(normal):
dir = random_unit_vector()
if dir.dot(normal) < 0:
dir = Vector3(-dir.x, -dir.y, -dir.z)
return dir
def render_image(width, height):
aspect_ratio = width / height
fov = np.pi / 3 # 60 degrees field of view
image = np.zeros((height, width, 3))
for y in range(height):
for x in range(width):
# Convert pixel coordinate to camera ray
px = (2 * (x + 0.5) / width - 1) * np.tan(fov / 2) * aspect_ratio
py = (1 - 2 * (y + 0.5) / height) * np.tan(fov / 2)
ray_origin = Vector3(0, 0, 0)
ray_direction = Vector3(px, py, -1).normalize()
color = trace_ray(ray_origin, ray_direction)
image[y, x, :] = np.clip(color, 0, 1)
return image
def trace_ray(ray_origin, ray_direction):
closest_t = np.inf
hit_object = None
hit_info = None
# Find the nearest intersection
for obj in objects:
result = obj.intersect(ray_origin, ray_direction)
if result:
t, hit_point, normal = result
if t < closest_t:
closest_t = t
hit_object = obj
hit_info = (hit_point, normal, obj.color)
if hit_object:
hit_point, normal, color = hit_info
direct_light = compute_direct_light(hit_point, normal)
indirect_light = estimate_radiance(hit_point, normal)
return color * (direct_light + indirect_light)
else:
return np.array([0, 0, 0]) # Background color
def compute_direct_light(point, normal):
# Simple Lambertian reflection from light source
direction_to_light = (light_position - point).normalize()
# Shadow ray
shadow_origin = point + normal * 1e-5
shadow_ray = direction_to_light
in_shadow = False
for obj in objects:
result = obj.intersect(shadow_origin, shadow_ray)
if result:
in_shadow = True
break
if in_shadow:
return np.array([0, 0, 0])
else:
intensity = max(0, normal.dot(direction_to_light))
return intensity * light_power / (4 * np.pi * (light_position - point).norm()**2)
def estimate_radiance(point, normal):
# Gather photons within the gather_radius
accumulated_power = np.array([0.0, 0.0, 0.0])
for photon_pos, photon_power in photon_map:
distance = (photon_pos - point).norm()
if distance < gather_radius:
weight = max(0, normal.dot((photon_pos - point).normalize()))
accumulated_power += photon_power * weight
area = np.pi * gather_radius ** 2
return accumulated_power / (area * num_photons)
# Main execution
if __name__ == '__main__':
print("Emitting photons...")
emit_photons()
print("Rendering image...")
width = 200
height = 100
image = render_image(width, height)
# Display the image
plt.imshow(image)
plt.axis('off')
plt.show()

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@ -7,8 +7,10 @@ resolution = 400x300
output = output.png
[ray_tracing]
max_depth = 5 ; Params for ray tracing
max_depth = 5
samples_per_pixel = 6
[photon_mapping]
photon_count = 100000 ; Params for photon mapping
num_photons = 10000
max_depth = 5
gather_radius = 0.5

19
main.py
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@ -1,10 +1,10 @@
import argparse
from configparser import ConfigParser
from rendering import ray_trace
from utils import load_config, parse_resolution
import importlib
import os
# from scenes.cornell_box import *
import matplotlib.pyplot as plt
from photon_mapping import render_photon_mapping
def main():
# default config
@ -22,6 +22,12 @@ def main():
parser.add_argument("--output", type=str, default=config.get('DEFAULT', 'output'), help="Output file name.")
parser.add_argument('--num_spheres', type=int, default=3, help='Number of spheres in the scene for Ray Tracing 0')
parser.add_argument('--num_photons', type=int, default=config.getint('photon_mapping', 'num_photons'), help='Number of photons for photon mapping')
parser.add_argument('--max_depth', type=int, default=config.getint('photon_mapping', 'max_depth'),
help='Maximum depth for photon tracing')
parser.add_argument('--gather_radius', type=float, default=config.getfloat('photon_mapping', 'gather_radius'),
help='Radius for radiance estimation in photon mapping')
args = parser.parse_args()
@ -53,6 +59,15 @@ def main():
img.save(output_path)
print(f"Image saved to {output_path}")
img.show()
elif args.algorithm == "photon_mapping":
print("Starting photon mapping...")
image = render_photon_mapping(width, height, args.num_photons, args.max_depth, args.gather_radius)
plt.imshow(image)
plt.axis('off')
output_path = os.path.join("outputs", args.output)
plt.savefig(output_path)
print(f"Image saved to {output_path}")
plt.show()
else:
print(f"Unknown algorithm: {args.algorithm}")
return

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photon_mapping.py Normal file
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@ -0,0 +1,191 @@
import numpy as np
import matplotlib.pyplot as plt
# Define basic vector operations
class Vector3:
def __init__(self, x, y, z):
self.x = x
self.y = y
self.z = z
def __add__(self, other):
return Vector3(self.x + other.x, self.y + other.y, self.z + other.z)
def __sub__(self, other):
return Vector3(self.x - other.x, self.y - other.y, self.z - other.z)
def __mul__(self, scalar):
return Vector3(self.x * scalar, self.y * scalar, self.z * scalar)
def dot(self, other):
return self.x * other.x + self.y * other.y + self.z * other.z
def norm(self):
return np.sqrt(self.dot(self))
def normalize(self):
n = self.norm()
return Vector3(self.x / n, self.y / n, self.z / n)
class Photon:
def __init__(self, position, direction, power):
self.position = position
self.direction = direction
self.power = power
class Sphere:
def __init__(self, center, radius, color):
self.center = center
self.radius = radius
self.color = color
def intersect(self, ray_origin, ray_direction):
oc = ray_origin - self.center
a = ray_direction.dot(ray_direction)
b = 2.0 * oc.dot(ray_direction)
c = oc.dot(oc) - self.radius * self.radius
discriminant = b * b - 4 * a * c
if discriminant < 0:
return None
else:
t = (-b - np.sqrt(discriminant)) / (2.0 * a)
if t < 0:
t = (-b + np.sqrt(discriminant)) / (2.0 * a)
if t < 0:
return None
hit_point = ray_origin + ray_direction * t
normal = (hit_point - self.center).normalize()
return (t, hit_point, normal)
class Plane:
def __init__(self, point, normal, color):
self.point = point
self.normal = normal.normalize()
self.color = color
def intersect(self, ray_origin, ray_direction):
denom = self.normal.dot(ray_direction)
if abs(denom) > 1e-6:
t = (self.point - ray_origin).dot(self.normal) / denom
if t >= 0:
hit_point = ray_origin + ray_direction * t
return (t, hit_point, self.normal)
return None
def render_photon_mapping(width, height, num_photons, max_depth, gather_radius):
# Photon mapping logic
photon_map = []
sphere = Sphere(Vector3(0, 0, -5), 1.0, np.array([1, 0, 0])) # Red sphere
plane = Plane(Vector3(0, -1, 0), Vector3(0, 1, 0), np.array([0.5, 0.5, 0.5])) # Gray plane
objects = [sphere, plane]
light_position = Vector3(-5, 5, -5)
light_power = np.array([1, 1, 1]) * 1000
def emit_photons():
for _ in range(num_photons):
direction = random_unit_vector()
power = light_power / num_photons
photon = Photon(light_position, direction, power)
trace_photon(photon, 0)
def trace_photon(photon, depth):
if depth > max_depth:
return
closest_t = np.inf
hit_object = None
hit_info = None
for obj in objects:
result = obj.intersect(photon.position, photon.direction)
if result:
t, hit_point, normal = result
if t < closest_t:
closest_t = t
hit_object = obj
hit_info = (hit_point, normal)
if hit_object:
hit_point, normal = hit_info
photon_map.append((hit_point, photon.power))
new_direction = random_hemisphere_direction(normal)
photon.position = hit_point
photon.direction = new_direction
photon.power = photon.power * 0.8
trace_photon(photon, depth + 1)
def random_unit_vector():
theta = np.random.uniform(0, 2 * np.pi)
z = np.random.uniform(-1, 1)
r = np.sqrt(1 - z * z)
return Vector3(r * np.cos(theta), r * np.sin(theta), z)
def random_hemisphere_direction(normal):
dir = random_unit_vector()
if dir.dot(normal) < 0:
dir = Vector3(-dir.x, -dir.y, -dir.z)
return dir
def trace_ray(ray_origin, ray_direction):
closest_t = np.inf
hit_object = None
hit_info = None
for obj in objects:
result = obj.intersect(ray_origin, ray_direction)
if result:
t, hit_point, normal = result
if t < closest_t:
closest_t = t
hit_object = obj
hit_info = (hit_point, normal, obj.color)
if hit_object:
hit_point, normal, color = hit_info
direct_light = compute_direct_light(hit_point, normal)
indirect_light = estimate_radiance(hit_point, normal)
return color * (direct_light + indirect_light)
else:
return np.array([0, 0, 0])
def compute_direct_light(point, normal):
direction_to_light = (light_position - point).normalize()
shadow_origin = point + normal * 1e-5
shadow_ray = direction_to_light
in_shadow = False
for obj in objects:
result = obj.intersect(shadow_origin, shadow_ray)
if result:
in_shadow = True
break
if in_shadow:
return np.array([0, 0, 0])
else:
intensity = max(0, normal.dot(direction_to_light))
return intensity * light_power / (4 * np.pi * (light_position - point).norm() ** 2)
def estimate_radiance(point, normal):
accumulated_power = np.array([0.0, 0.0, 0.0])
for photon_pos, photon_power in photon_map:
distance = (photon_pos - point).norm()
if distance < gather_radius:
weight = max(0, normal.dot((photon_pos - point).normalize()))
accumulated_power += photon_power * weight
area = np.pi * gather_radius ** 2
return accumulated_power / area
emit_photons()
aspect_ratio = width / height
fov = np.pi / 3
image = np.zeros((height, width, 3))
for y in range(height):
for x in range(width):
px = (2 * (x + 0.5) / width - 1) * np.tan(fov / 2) * aspect_ratio
py = (1 - 2 * (y + 0.5) / height) * np.tan(fov / 2)
ray_origin = Vector3(0, 0, 0)
ray_direction = Vector3(px, py, -1).normalize()
color = trace_ray(ray_origin, ray_direction)
image[y, x, :] = np.clip(color, 0, 1)
return image