def create_stairs_packet(num_steps):
assert mitsuba.variant() == 'packet_rgb'
from mitsuba.render import Mesh
size_step = 1.0 / num_steps
m = Mesh("stairs", vertex_struct, 4 * num_steps, index_struct,
4 * num_steps - 2)
v = m.vertices()
f = m.faces()
for i in range(num_steps):
h = i * size_step
s1 = i * size_step
s2 = (i + 1) * size_step
k = 4 * i
v[k + 0] = (0.0, s1, h)
v[k + 1] = (1.0, s1, h)
v[k + 2] = (0.0, s2, h)
v[k + 3] = (1.0, s2, h)
f[k] = (k, k + 1, k + 2)
f[k + 1] = (k + 1, k + 3, k + 2)
if i < num_steps - 1:
f[k + 2] = (k + 2, k + 3, k + 5)
f[k + 3] = (k + 5, k + 4, k + 2)
m.recompute_bbox()
return m
def create_single_triangle():
from mitsuba.render import Mesh
m = Mesh("tri", vertex_struct, 3, index_struct, 1)
v = m.vertices()
f = m.faces()
v[0] = (0, 0, 0)
v[1] = (1, 0.2, 0)
v[2] = (0.2, 1, 0)
f[0] = (0, 1, 2)
m.recompute_bbox()
return m
def create_regular_tetrahedron():
from mitsuba.render import Mesh
m = Mesh("tetrahedron", vertex_struct, 4, index_struct, 4)
v = m.vertices()
f = m.faces()
v[0] = (0, 0, 0)
v[1] = (0.8, 0.8, 0)
v[2] = (0.8, 0, 0.8)
v[3] = (0, 0.8, 0.8)
f[0] = (0, 1, 2)
f[1] = (2, 3, 0)
f[2] = (2, 1, 3)
f[3] = (3, 1, 0)
m.recompute_bbox()
return m
def test04_normal_weighting_scheme(variant_scalar_rgb):
from mitsuba.core import Struct, float_dtype, Vector3f
from mitsuba.render import Mesh
import numpy as np
"""Tests the weighting scheme that is used to compute surface normals."""
vertex_struct = Struct() \
.append("x", Struct.Type.Float32) \
.append("y", Struct.Type.Float32) \
.append("z", Struct.Type.Float32) \
.append("nx", Struct.Type.Float32) \
.append("ny", Struct.Type.Float32) \
.append("nz", Struct.Type.Float32)
index_struct = Struct() \
.append("i0", Struct.Type.UInt32) \
.append("i1", Struct.Type.UInt32) \
.append("i2", Struct.Type.UInt32)
m = Mesh("MyMesh", vertex_struct, 5, index_struct, 2)
v = m.vertices()
a, b = 1.0, 0.5
v['x'] = Float([0, -a, a, -b, b])
v['y'] = Float([0, 1, 1, 0, 0])
v['z'] = Float([0, 0, 0, 1, 1])
n0 = Vector3f(0.0, 0.0, -1.0)
n1 = Vector3f(0.0, 1.0, 0.0)
angle_0 = ek.pi / 2.0
angle_1 = ek.acos(3.0 / 5.0)
n2 = n0 * angle_0 + n1 * angle_1
n2 /= ek.norm(n2)
n = np.vstack([n2, n0, n0, n1, n1])
f = m.faces()
f[0] = (0, 1, 2)
f[1] = (0, 3, 4)
m.recompute_vertex_normals()
assert ek.allclose(v['nx'], n[:, 0], 5e-4)
assert ek.allclose(v['ny'], n[:, 1], 5e-4)
assert ek.allclose(v['nz'], n[:, 2], 5e-4)
