def IndexedNormals(V, F):
'''
Keep the face index, and provide one normal per vertex
'''
# normals = np.ndarray((len(V)*3,3), dtype=np.float32)
normals = [[] for x in range(len(V))]
A = [[] for x in range(len(V))]
# normals = np.ndarray((len(F)*3,3), dtype=np.float32)
x = 0
for f in F:
p0, p1, p2 = [V[f[x]] for x in range(3)]
n = _v.cross(_v.vector(p0, p1), _v.vector(p0, p2))
for i in range(3): # in triangle
# print (f[i] , n)
# normals[x].append(n) # append the face normal
# normals[x].append(f[i]) # keep the vertex index
normals[f[i]].append(n) # would index the normal by face
# compute the adjacency list while we are in
A[f[i]] += [fa for fa in f if fa != f[i] and fa not in A[f[i]]]
x += 1
for i, n in enumerate(normals):
# print(n,len(n),_v.sum(*n), _v.div(float(len(n)),_v.sum(*n)))
# weighted by the number of face = wrong
normals[i] = _v.div(float(len(n)), _v.sum(*n))
# print('>',normals[i])
# print('#',A)
# print('//',normals, len(normals))
return normals
def vertexAndNormalsList(V, F):
'''
one normal per faces = one normal for each distinct vertices
no shared verts. Gouraud Shading, diamond sharp edges
the unormalized normals list, indexed on the vertex list
unormalized = relative to the surface of the face.
check the influence of the face size on the illumination model
'''
vertices = np.ndarray((len(F) * 3, 3), dtype=np.float32)
normals = np.ndarray((len(F) * 3, 3), dtype=np.float32)
x = 0
for f in F:
p0, p1, p2 = [V[f[y]] for y in range(3)]
n = _v.cross(_v.vector(p0, p1), _v.vector(p0, p2))
for i in range(3):
vertices[x] = V[f[i]] # flatten / recopy the vertex
# the three vertex hold the same normal value
normals[x] = _v.div(_v.mag(n), n)
x += 1
return vertices, normals
[4, 5, 0, 1],
]
def rgb(x, y, z):
return x / 2 + .5, y / 2 + .5, z / 2 + .5
sizes = []
# noinspection SpellCheckingInspection
verticies, normals, colors = [], [], []
for indexes in faces:
sizes.append(len(indexes))
p0, p1, p2 = [points[indexes[i]] for i in range(3)]
normal = _v.cross(_v.vector(p0, p1), _v.vector(p0, p2))
for index in indexes:
vertex = points[index]
verticies.append(vertex)
normals.append(normal)
colors.append(rgb(*vertex))
# noinspection SpellCheckingInspection
tex_coords = verticies
# noinspection SpellCheckingInspection
indicies = list(range(sum(sizes)))
# noinspection SpellCheckingInspection
__all__ = [
"sizes",
"indicies",