def _trackball_point(self, point):
n_point = self._nearplane_point(point)
v = n_point - self.prev_pos
v /= np.sqrt(v.dot(v))
l = self.prev_ref - self.prev_pos
ll = l.dot(l)
t = l.dot(v)
dd = max(0.0, ll - t * t)
d = np.sqrt(dd)
r = min(self.radius, np.sqrt(l.dot(l)) - self.near)
rr = r * r
len_l = np.sqrt(ll)
unit_l = l / len_l
axis = np.cross(unit_l, v)
if dd > rr:
sin = r / len_l
s = np.sqrt(ll - rr)
cos = s / len_l
q = qt.from_axis_and_angle(axis, sin, cos)
p = self.prev_pos + s * qt.rotate(q, unit_l)
else: # intersects
sin = d / len_l
cos = t / len_l
q = qt.from_axis_and_angle(axis, sin, cos)
dt = np.sqrt(rr - dd)
t -= dt
p = self.prev_pos + t * qt.rotate(q, unit_l)
return p
def rotate(self, target):
s = self.t_source - self.prev_ref
e = self._trackball_point(target) - self.prev_ref
q = ~qt.from_two_vectors(s, e)
v = self.prev_pos - self.prev_ref
self.pos = self.prev_ref + qt.rotate(q, v)
self.up = qt.rotate(q, self.prev_up)
self._look_at()
def rotate(self, rot_about, theta):
"""rot_about = unit vector to rotate about
theta = radians"""
r = quaternion.rotate([self.vec[0][0], self.vec[1][0], self.vec[2][0]],
[rot_about[0], rot_about[1], rot_about[2]],
theta)
return Position(r[0], r[1], r[2])
def roll(self, phi):
"""Roll camera, positive phi right."""
self.up = quat.rotate(self.up, self.forward, phi).normalize()
def yaw(self, phi):
"""Yaw camera, positive phi right."""
self.forward = quat.rotate(self.forward, self.up, -phi).normalize()
def pitch(self, phi):
"""Pitch camera, positive phi down."""
left = (self.up @ self.forward).normalize()
self.forward = quat.rotate(self.forward, left, phi).normalize()
self.up = quat.rotate(self.up, left, phi).normalize()
def rotateZ(self, theta):
r = quaternion.rotate([self.vec[0][0], self.vec[1][0], self.vec[2][0]],
[0, 0, 1], theta)
return Position(r[0], r[1], r[2])
def rotateZ(self, theta):
p = quaternion.rotate(self.pos, [0, 0, 1], theta)
uv = quaternion.rotate(self.upvec, [0, 0, 1], theta)
return Position.VCam(p, uv)
def roll(self, phi):
"""Roll camera, positive phi right."""
self.up = quat.rotate(self.up, self.forward, phi).normalize()
def yaw(self, phi):
"""Yaw camera, positive phi right."""
self.forward = quat.rotate(self.forward, self.up, -phi).normalize()
def pitch(self, phi):
"""Pitch camera, positive phi down."""
left = (self.up @ self.forward).normalize()
self.forward = quat.rotate(self.forward, left, phi).normalize()
self.up = quat.rotate(self.up, left, phi).normalize()
