def update_shadow(self):
point = self.get_source_point()
projected_screen_points = []
if not self.has_screen():
return
for point in self.screen.get_anchors():
projected_screen_points.append(self.spotlight.project(point))
projected_source = project_along_vector(
self.get_source_point(), self.spotlight.projection_direction())
projected_point_cloud_3d = np.append(projected_screen_points,
np.reshape(
projected_source, (1, 3)),
axis=0)
# z_to_vector(self.spotlight.projection_direction())
rotation_matrix = self.rotation_matrix()
back_rotation_matrix = rotation_matrix.T # i. e. its inverse
rotated_point_cloud_3d = np.dot(projected_point_cloud_3d,
back_rotation_matrix.T)
# these points now should all have z = 0
point_cloud_2d = rotated_point_cloud_3d[:, :2]
# now we can compute the convex hull
hull_2d = ConvexHull(point_cloud_2d) # guaranteed to run ccw
hull = []
# we also need the projected source point
source_point_2d = np.dot(
self.spotlight.project(self.get_source_point()),
back_rotation_matrix.T)[:2]
index = 0
for point in point_cloud_2d[hull_2d.vertices]:
if np.all(np.abs(point - source_point_2d) < 1.0e-6):
source_index = index
index += 1
continue
point_3d = np.array([point[0], point[1], 0])
hull.append(point_3d)
index += 1
hull_mobject = VMobject()
hull_mobject.set_points_as_corners(hull)
hull_mobject.apply_matrix(rotation_matrix)
anchors = hull_mobject.get_anchors()
# add two control points for the outer cone
if np.size(anchors) == 0:
self.shadow.points = []
return
ray1 = anchors[source_index - 1] - projected_source
ray1 = ray1 / get_norm(ray1) * 100
ray2 = anchors[source_index] - projected_source
ray2 = ray2 / get_norm(ray2) * 100
outpoint1 = anchors[source_index - 1] + ray1
outpoint2 = anchors[source_index] + ray2
new_anchors = anchors[:source_index]
new_anchors = np.append(new_anchors,
np.array([outpoint1, outpoint2]),
axis=0)
new_anchors = np.append(new_anchors, anchors[source_index:], axis=0)
self.shadow.set_points_as_corners(new_anchors)
# shift it closer to the camera so it is in front of the spotlight
self.shadow.mark_paths_closed = True
def update_shadow(self):
point = self.get_source_point()
projected_screen_points = []
if not self.has_screen():
return
for point in self.screen.get_anchors():
projected_screen_points.append(self.spotlight.project(point))
projected_source = project_along_vector(
self.get_source_point(), self.spotlight.projection_direction())
projected_point_cloud_3d = np.append(
projected_screen_points,
np.reshape(projected_source, (1, 3)),
axis=0
)
# z_to_vector(self.spotlight.projection_direction())
rotation_matrix = self.rotation_matrix()
back_rotation_matrix = rotation_matrix.T # i. e. its inverse
rotated_point_cloud_3d = np.dot(
projected_point_cloud_3d, back_rotation_matrix.T)
# these points now should all have z = 0
point_cloud_2d = rotated_point_cloud_3d[:, :2]
# now we can compute the convex hull
hull_2d = ConvexHull(point_cloud_2d) # guaranteed to run ccw
hull = []
# we also need the projected source point
source_point_2d = np.dot(self.spotlight.project(
self.get_source_point()), back_rotation_matrix.T)[:2]
index = 0
for point in point_cloud_2d[hull_2d.vertices]:
if np.all(np.abs(point - source_point_2d) < 1.0e-6):
source_index = index
index += 1
continue
point_3d = np.array([point[0], point[1], 0])
hull.append(point_3d)
index += 1
hull_mobject = VMobject()
hull_mobject.set_points_as_corners(hull)
hull_mobject.apply_matrix(rotation_matrix)
anchors = hull_mobject.get_anchors()
# add two control points for the outer cone
if np.size(anchors) == 0:
self.shadow.points = []
return
ray1 = anchors[source_index - 1] - projected_source
ray1 = ray1 / get_norm(ray1) * 100
ray2 = anchors[source_index] - projected_source
ray2 = ray2 / get_norm(ray2) * 100
outpoint1 = anchors[source_index - 1] + ray1
outpoint2 = anchors[source_index] + ray2
new_anchors = anchors[:source_index]
new_anchors = np.append(new_anchors, np.array(
[outpoint1, outpoint2]), axis=0)
new_anchors = np.append(new_anchors, anchors[source_index:], axis=0)
self.shadow.set_points_as_corners(new_anchors)
# shift it closer to the camera so it is in front of the spotlight
self.shadow.mark_paths_closed = True
def project(self, point):
v = self.projection_direction()
w = project_along_vector(point, v)
return w
def project(self, point):
v = self.projection_direction()
w = project_along_vector(point, v)
return w