new geometry class. beginning to implement physics by defining a material class; each triangle will have a material linked to both of its sides

1 files changed, 47 insertions, 0 deletions

diff --git a/bvh.py b/bvh.py
new file mode 100644
index 0000000..d1e4c1a
--- /dev/null
+++ b/bvh.py
@@ -0,0 +1,47 @@
+import numpy as np
+from itertools import chain
+
+def compress(data, selectors):
+    return (d for d, s in zip(data, selectors) if s)
+
+class Leaf(object):
+    def __init__(self, mesh, mesh_idx, zvalue=None):
+        self.mesh_idx = mesh_idx
+        self.size = mesh.shape[0]
+        self.zvalue = zvalue
+        self.lower_bound = np.array([np.min(mesh[:,:,0]), np.min(mesh[:,:,1]), np.min(mesh[:,:,2])])
+        self.upper_bound = np.array([np.max(mesh[:,:,0]), np.max(mesh[:,:,1]), np.max(mesh[:,:,2])])
+        self.center = (self.lower_bound + self.upper_bound)/2.0
+
+class Node(object):
+    def __init__(self, children, zvalue=None):
+        self.size = len(children)
+        self.zvalue = zvalue
+
+        lower_pts = np.array([child.lower_bound for child in children])
+        upper_pts = np.array([child.upper_bound for child in children])
+
+        self.lower_bound = np.array([np.min(lower_pts[:,0]), np.min(lower_pts[:,1]), np.min(lower_pts[:,2])])
+        self.upper_bound = np.array([np.max(upper_pts[:,0]), np.max(upper_pts[:,1]), np.max(upper_pts[:,2])])
+
+        self.children = children
+
+        self.center = (self.lower_bound + self.upper_bound)/2.0
+
+def interleave(*args):
+    return int("".join(chain(*zip(*[bin(x)[2:].zfill(x.nbytes*8) for x in args]))), 2)
+
+def morton_order(mesh, bits=8):
+    lower_bound = np.array([np.min(mesh[:,:,0]), np.min(mesh[:,:,1]), np.min(mesh[:,:,2])])
+    upper_bound = np.array([np.max(mesh[:,:,0]), np.max(mesh[:,:,1]), np.max(mesh[:,:,2])])
+    
+    def quantize(x):
+        return np.uint64((x-lower_bound)*bits/(upper_bound-lower_bound))
+
+    zvalues = np.empty(mesh.shape[0], dtype=np.uint64)
+    for i, triangle in enumerate(mesh):
+        zvalues[i] = interleave(*quantize(np.mean(triangle, axis=0)))
+
+    order = np.array(zip(*sorted(zip(zvalues, range(len(zvalues)))))[-1])
+
+    return order, zvalues