1 files changed, 42 insertions, 0 deletions
diff --git a/chroma/demo/checkerboard.py b/chroma/demo/checkerboard.py
new file mode 100644
index 0000000..dd2e3e1
--- /dev/null
+++ b/chroma/demo/checkerboard.py
@@ -0,0 +1,42 @@
+import numpy as np
+from chroma.itertoolset import *
+from chroma.geometry import Mesh, Solid, Geometry
+from chroma.make import sphere
+
+from chroma.demo.optics import *
+
+def build_checkerboard_scene(checkers_per_side=10, squares_per_checker=50):
+    x = np.linspace(-5.0, 5.0, checkers_per_side*squares_per_checker+1)
+    y = np.linspace(-5.0, 5.0, checkers_per_side*squares_per_checker+1)
+
+    vertices = np.array(tuple(product(x,y,[0])))
+
+    triangles = []
+    for j in range(y.size-1):
+        for i in range(x.size-1):
+            triangles.append([j*len(x)+i, (j+1)*len(x)+i,(j+1)*len(x)+i+1]) 
+            triangles.append([j*len(x)+i, j*len(x)+i+1,(j+1)*len(x)+i+1]) 
+
+    checkerboard_mesh = Mesh(vertices, triangles, remove_duplicate_vertices=True)
+
+    checkerboard_color_line1 = take(checkers_per_side*squares_per_checker*2, cycle([0]*2*squares_per_checker + [0xffffff]*2*squares_per_checker))*squares_per_checker
+    checkerboard_color_line2 = take(checkers_per_side*squares_per_checker*2, cycle([0xffffff]*2*squares_per_checker + [0]*2*squares_per_checker))*squares_per_checker
+    checkerboard_color = take(len(checkerboard_mesh.triangles), cycle(checkerboard_color_line1 + checkerboard_color_line2))
+
+    checkerboard_surface_line1 = take(checkers_per_side*squares_per_checker*2, cycle([black_surface]*2*squares_per_checker + [lambertian_surface]*2*squares_per_checker))*squares_per_checker
+    checkerboard_surface_line2 = take(checkers_per_side*squares_per_checker*2, cycle([lambertian_surface]*2*squares_per_checker + [black_surface]*2*squares_per_checker))*squares_per_checker
+    checkerboard_surface = take(len(checkerboard_mesh.triangles), cycle(checkerboard_surface_line1 + checkerboard_surface_line2))
+
+    checkerboard = Solid(checkerboard_mesh, vacuum, vacuum, surface=checkerboard_surface, color=checkerboard_color)
+
+    sphere1 = Solid(sphere(nsteps=512), water, vacuum)
+    sphere2 = Solid(sphere(nsteps=512), vacuum, vacuum, surface=shiny_surface)
+    sphere3 = Solid(sphere(nsteps=512), vacuum, vacuum, surface=lambertian_surface)
+
+    checkerboard_scene = Geometry()
+    checkerboard_scene.add_solid(checkerboard, displacement=(0,0,-1.5))
+    checkerboard_scene.add_solid(sphere1, displacement=(2.0,-2.0,0))
+    checkerboard_scene.add_solid(sphere2, displacement=(-2.0,-2.0,0))
+    checkerboard_scene.add_solid(sphere3, displacement=(0.0,2.0,0))
+
+    return checkerboard_scene