add library for projecting rays in different ways.

1 files changed, 28 insertions, 0 deletions

diff --git a/project.py b/project.py
new file mode 100644
index 0000000..801a4de
--- /dev/null
+++ b/project.py
@@ -0,0 +1,28 @@
+import numpy as np
+from itertools import repeat
+from chroma.transform import rotate
+
+def from_film(position, axis1=(0,0,1), axis2=(1,0,0), size=(800,600), width=0.035, focal_length=0.018):
+    height = width*(size[1]/float(size[0]))
+
+    x = np.linspace(width/2, -width/2, size[0])
+    z = np.linspace(-height/2, height/2, size[1])
+
+    zz, xx = np.meshgrid(z,x)
+
+    grid = np.array(zip(xx.flatten(),repeat(0),zz.flatten()))
+
+    axis1 = np.asarray(axis1)/np.linalg.norm(axis1)
+    axis2 = np.asarray(axis2)/np.linalg.norm(axis2)
+
+    assert axis1.dot(axis2) == 0.0
+
+    if (axis1 != (0,0,1)).any():
+        grid = rotate(grid, np.arccos(axis1.dot((0,0,1))), np.cross(axis1,(0,0,1)))
+
+    if (axis2 != (1,0,0)).any():
+        grid = rotate(grid, np.arccos(axis2.dot((1,0,0))), np.cross(axis2,(1,0,0)))
+
+    grid -= np.cross(axis1,axis2)*focal_length
+
+    return grid+position, -grid/np.apply_along_axis(np.linalg.norm,1,grid)[:,np.newaxis]