def build_camera(json_file):
with open(json_file, 'r') as f:
json_data = json.load(f)
obj_node = hou.node('/obj')
cam_node = obj_node.createNode('cam', node_name=json_data['name'])
logging.info('Building %s camera', json_data['name'])
eye = hou.Vector3(json_data['eye'])
up = hou.Vector3(json_data['up'])
look = hou.Vector3(json_data['look'])
cam_node.parmTuple('t').set(json_data['eye'])
z = look - eye
x = up.cross(z)
y = z.cross(x)
# x axis is flipped from houdini
x = -x.normalized()
y = y.normalized()
z = z.normalized()
mat3 = hou.Matrix3((x, y, z))
cam_node.parmTuple('r').set(mat3.extractRotates())
cam_node.parmTuple('res').set((2048, int(2048 * 1.0 / json_data['ratio'])))
focal = json_data['focalLength']
cam_node.parm('focal').set(focal)
fov_rad = math.radians(json_data['fov'])
fov_ratio = (1.0 / math.tan(fov_rad * 0.5)) * 0.5
cam_node.parm('aperture').set(focal / fov_ratio)
cam_node.parm('focus').set(json_data['centerOfInterest'])
cam_node.parm('fstop').set(focal / (json_data['lensRadius'] * 2.0))
cam_node.parm('far').set(1.0e6)
create_rop(cam_node)
def extractBoxTransform(geo):
# Extrects Box Transforms from the geo
p = []
for prim in geo.prims():
p += [prim.positionAtInterior(0.5, 0.5)]
center = (p[4] + p[5]) * 0.5
dx = (p[1] - p[3]).length()
dy = (p[5] - p[4]).length()
dz = (p[2] - p[0]).length()
size = hou.Vector3(dx, dy, dz)
yax = (p[5] - p[4]).normalized()
xax = (p[1] - p[3]).normalized()
zax = (p[2] - p[0]).normalized()
m = hou.Matrix3([
xax.x(),
xax.y(),
xax.z(),
yax.x(),
yax.y(),
yax.z(),
zax.x(),
zax.y(),
zax.z()
])
rotates = m.extractRotates()
return [center, size, rotates]
def prim_transform(prim):
"""Return a tuple representing the Matrix4 of the transform intrinsic"""
rot_mat = hou.Matrix3(prim.intrinsicValue("transform"))
vtx = prim.vertex(0)
pt = vtx.point()
pos = pt.position()
xlate = hou.hmath.buildTranslate(pos)
return (hou.Matrix4(rot_mat) * xlate).asTuple()
def test_buildLookat(self):
TARGET = hou.Matrix3(
((0.70710678118654746, -0.0, 0.70710678118654746), (0.0, 1.0, 0.0),
(-0.70710678118654746, 0.0, 0.70710678118654746)))
lookAt = hou.hmath.buildLookat(hou.Vector3(0, 0, 1),
hou.Vector3(1, 0, 0),
hou.Vector3(0, 1, 0))
self.assertEqual(lookAt, TARGET)
def getTransform(self):
self.update()
if (self.__transmat is None):
rangle = radians(self.__localangle)
co = cos(rangle)
si = sin(rangle)
pos = self.__localposition
localmat = hou.Matrix3(
((co, si, 0.0), (-si, co, 0.0), (pos[0], pos[1], 1.0)))
if (self.__parent is not None):
self.__transmat = localmat * self.__parent.getTransform()
else:
self.__transmat = localmat
return self.__transmat
def test_m3ZeroIsNotIdentity(self):
m3 = hou.Matrix3()
self.assertFalse(m3.isIdentity())
def test_m3IdentIsIdentity(self):
m3 = hou.Matrix3()
m3.setToIdentity()
self.assertTrue(m3.isIdentity())
def test_getDual(self):
TARGET = hou.Matrix3(((0, -3, 2), (3, 0, -1), (-2, 1, 0)))
v3 = hou.Vector3(1, 2, 3)
self.assertEqual(v3.getDual(), TARGET)