Caribu with simple python object

This script demonstrate how to illuminate a scene with caribu algorithms using only simple python objects.

I. Create scene and lights

# define geometry of triangles points
triangle_1 = [(0, 0, 0), (1, 0, 0), (0, 1, 0)]
triangle_2  = [(0, 0, 1e-5), (1, 0, 1e-5), (0, 1, 1e-5)]

# define triangles list (scene)
triangles = [triangle_1, triangle_2]

# define optical property associate to triangle
material_triangle_1 = (0.06, 0.04) # reflectance & transmitance
material_triangle_2 = (0.06, 0.04) # reflectance & transmitance

# define materials list
materials = [material_triangle_1, material_triangle_2]

# create a zenital light
vertical_light = (100, # horizontal irradiance of the source
                  (0, 0, -1)) # direction vector of the source

# define light sources
lights = [vertical_light]

II. Scene illumination

II.1 Show result

def show_result(res):
    print("Index of the triangles : ", res['index'])
    print("The internal barcode : ", res['label'])
    print("The individual areas of triangles : ", res['area'])
    print("Surfacic density of energy : \n")
    print("\t- absorbed by the triangles : ", res['Eabs'])
    print("\t- incoming on the triangles :", res['Ei'])
    print("\t- incoming on the inferior face of the triangle", res['Ei_inf'])
    print("\t- incoming on the superior face of the triangle", res['Ei_sup'])

II.2 Raycasting

Raycasting allows to evaluate the direct illumination (first order = (no transmitance, no reflectance), without rediffusion) of a scene

from openalea.caribu.caribu import raycasting

# call raycasting algorithm for lightening the scene
res = raycasting(triangles, materials, lights)

show_result(res)

Index of the triangles :  [0.0, 1.0]
The internal barcode :  ['100001001000', '100001001000']
The individual areas of triangles :  [0.5, 0.5]
Surfacic density of energy :

    - absorbed by the triangles :  [0.0, 89.887321]
    - incoming on the triangles : [0.0, 99.87480111111111]
    - incoming on the inferior face of the triangle [0.0, 0.0]
    - incoming on the superior face of the triangle [0.0, 99.874802]

II.3 Radiosity

Radiosity allows to evaluate the exact illumination (all orders, with rediffusions) of a scene

from openalea.caribu.caribu import radiosity

res = radiosity(triangles, materials, lights)

show_result(res)

Index of the triangles :  [0.0, 1.0]
The internal barcode :  ['100001001000', '100001001000']
The individual areas of triangles :  [0.5, 0.5]
Surfacic density of energy :

    - absorbed by the triangles :  [3.615814, 90.104706]
    - incoming on the triangles : [4.017571111111111, 100.11634]
    - incoming on the inferior face of the triangle [0.0, 0.24154]
    - incoming on the superior face of the triangle [4.017571, 99.874802]

II.3 Mixed radiosity

Mixed radiosity allows to evaluate an optimised approximative solution of the illumination (all orders, with rediffusions) of an infinitly reapeated scene. The optimisation consists of using radiosity in a given neighbourhood and a turbid medium algorithm for the rest of the rediffusion.

from openalea.caribu.caribu import mixed_radiosity

# number of layers for running the turbid medium algrothm
layers = 2

# height of the canopy
height = 1

soil_reflectance = 0.2

# 2D Coordinates of the domain bounding the scene for its replication.
# (xmin, ymin, xmax, ymax)
domain = (0, 0, 1, 1)

# diameter of the sphere defining the close neighbourhood for local radiosity.
diameter = 0.1

res = mixed_radiosity(triangles, materials, lights, domain, soil_reflectance, diameter, layers, height)

show_result(res)

Index of the triangles :  [0.0, 1.0]
The internal barcode :  ['100001001000', '100001001000']
The individual areas of triangles :  [0.5, 0.5]
Surfacic density of energy :

    - absorbed by the triangles :  [3.620033, 90.209846]
    - incoming on the triangles : [4.022258888888889, 100.23316222222222]
    - incoming on the inferior face of the triangle [0.0, 0.241822]
    - incoming on the superior face of the triangle [4.022259, 99.991341]