3b1b-manim/manimlib/camera/three_d_camera.py

234 lines
8.4 KiB
Python

import numpy as np
from manimlib.camera.camera import Camera
from manimlib.constants import *
from manimlib.mobject.three_d_utils import get_3d_vmob_end_corner
from manimlib.mobject.three_d_utils import get_3d_vmob_end_corner_unit_normal
from manimlib.mobject.three_d_utils import get_3d_vmob_start_corner
from manimlib.mobject.three_d_utils import get_3d_vmob_start_corner_unit_normal
from manimlib.mobject.types.point_cloud_mobject import Point
from manimlib.mobject.types.vectorized_mobject import VMobject
from manimlib.mobject.value_tracker import ValueTracker
from manimlib.utils.color import get_shaded_rgb
from manimlib.utils.simple_functions import clip_in_place
from manimlib.utils.space_ops import center_of_mass
from manimlib.utils.space_ops import rotation_about_z
from manimlib.utils.space_ops import rotation_matrix
class ThreeDCamera(Camera):
CONFIG = {
"shading_factor": 0.2,
"distance": 20.0,
"default_distance": 5.0,
"phi": 0, # Angle off z axis
"theta": -90 * DEGREES, # Rotation about z axis
"gamma": 0, # Rotation about normal vector to camera
"light_source_start_point": 9 * DOWN + 7 * LEFT + 10 * OUT,
"frame_center": ORIGIN,
"should_apply_shading": True,
"exponential_projection": False,
"max_allowable_norm": 3 * FRAME_WIDTH,
}
def __init__(self, *args, **kwargs):
Camera.__init__(self, *args, **kwargs)
self.phi_tracker = ValueTracker(self.phi)
self.theta_tracker = ValueTracker(self.theta)
self.distance_tracker = ValueTracker(self.distance)
self.gamma_tracker = ValueTracker(self.gamma)
self.light_source = Point(self.light_source_start_point)
self.frame_center = Point(self.frame_center)
self.fixed_orientation_mobjects = dict()
self.fixed_in_frame_mobjects = set()
self.reset_rotation_matrix()
def capture_mobjects(self, mobjects, **kwargs):
self.reset_rotation_matrix()
Camera.capture_mobjects(self, mobjects, **kwargs)
def get_value_trackers(self):
return [
self.phi_tracker,
self.theta_tracker,
self.distance_tracker,
self.gamma_tracker,
]
def modified_rgbas(self, vmobject, rgbas):
if not self.should_apply_shading:
return rgbas
if vmobject.shade_in_3d and (vmobject.get_num_points() > 0):
light_source_point = self.light_source.points[0]
if len(rgbas) < 2:
shaded_rgbas = rgbas.repeat(2, axis=0)
else:
shaded_rgbas = np.array(rgbas[:2])
shaded_rgbas[0, :3] = get_shaded_rgb(
shaded_rgbas[0, :3],
get_3d_vmob_start_corner(vmobject),
get_3d_vmob_start_corner_unit_normal(vmobject),
light_source_point,
)
shaded_rgbas[1, :3] = get_shaded_rgb(
shaded_rgbas[1, :3],
get_3d_vmob_end_corner(vmobject),
get_3d_vmob_end_corner_unit_normal(vmobject),
light_source_point,
)
return shaded_rgbas
return rgbas
def get_stroke_rgbas(self, vmobject, background=False):
return self.modified_rgbas(
vmobject, vmobject.get_stroke_rgbas(background)
)
def get_fill_rgbas(self, vmobject):
return self.modified_rgbas(
vmobject, vmobject.get_fill_rgbas()
)
def get_mobjects_to_display(self, *args, **kwargs):
mobjects = Camera.get_mobjects_to_display(
self, *args, **kwargs
)
rot_matrix = self.get_rotation_matrix()
def z_key(mob):
if not (hasattr(mob, "shade_in_3d") and mob.shade_in_3d):
return np.inf
# Assign a number to a three dimensional mobjects
# based on how close it is to the camera
return np.dot(
mob.get_z_index_reference_point(),
rot_matrix.T
)[2]
return sorted(mobjects, key=z_key)
def get_phi(self):
return self.phi_tracker.get_value()
def get_theta(self):
return self.theta_tracker.get_value()
def get_distance(self):
return self.distance_tracker.get_value()
def get_gamma(self):
return self.gamma_tracker.get_value()
def get_frame_center(self):
return self.frame_center.points[0]
def set_phi(self, value):
self.phi_tracker.set_value(value)
def set_theta(self, value):
self.theta_tracker.set_value(value)
def set_distance(self, value):
self.distance_tracker.set_value(value)
def set_gamma(self, value):
self.gamma_tracker.set_value(value)
def set_frame_center(self, point):
self.frame_center.move_to(point)
def reset_rotation_matrix(self):
self.rotation_matrix = self.generate_rotation_matrix()
def get_rotation_matrix(self):
return self.rotation_matrix
def generate_rotation_matrix(self):
phi = self.get_phi()
theta = self.get_theta()
gamma = self.get_gamma()
matrices = [
rotation_about_z(-theta - 90 * DEGREES),
rotation_matrix(-phi, RIGHT),
rotation_about_z(gamma),
]
result = np.identity(3)
for matrix in matrices:
result = np.dot(matrix, result)
return result
def project_points(self, points):
frame_center = self.get_frame_center()
distance = self.get_distance()
rot_matrix = self.get_rotation_matrix()
points = points - frame_center
points = np.dot(points, rot_matrix.T)
zs = points[:, 2]
for i in 0, 1:
if self.exponential_projection:
# Proper projedtion would involve multiplying
# x and y by d / (d-z). But for points with high
# z value that causes weird artifacts, and applying
# the exponential helps smooth it out.
factor = np.exp(zs / distance)
lt0 = zs < 0
factor[lt0] = (distance / (distance - zs[lt0]))
else:
factor = (distance / (distance - zs))
factor[(distance - zs) < 0] = 10**6
# clip_in_place(factor, 0, 10**6)
points[:, i] *= factor
points = points + frame_center
return points
def project_point(self, point):
return self.project_points(point.reshape((1, 3)))[0, :]
def transform_points_pre_display(self, mobject, points):
fixed_orientation = mobject in self.fixed_orientation_mobjects
fixed_in_frame = mobject in self.fixed_in_frame_mobjects
if fixed_in_frame:
return points
if fixed_orientation:
# center = center_of_mass(points)
center_func = self.fixed_orientation_mobjects[mobject]
center = center_func()
new_center = self.project_point(center)
return points + (new_center - center)
else:
return self.project_points(points)
def add_fixed_orientation_mobjects(
self, *mobjects,
use_static_center_func=False,
center_func=None):
# This prevents the computation of mobject.get_center
# every single time a projetion happens
def get_static_center_func(mobject):
point = mobject.get_center()
return (lambda: point)
for mobject in mobjects:
if center_func:
func = center_func
elif use_static_center_func:
func = get_static_center_func(mobject)
else:
func = mobject.get_center
for submob in mobject.get_family():
self.fixed_orientation_mobjects[submob] = func
def add_fixed_in_frame_mobjects(self, *mobjects):
for mobject in self.extract_mobject_family_members(mobjects):
self.fixed_in_frame_mobjects.add(mobject)
def remove_fixed_orientation_mobjects(self, *mobjects):
for mobject in self.extract_mobject_family_members(mobjects):
if mobject in self.fixed_orientation_mobjects:
self.fixed_orientation_mobjects.remove(mobject)
def remove_fixed_in_frame_mobjects(self, *mobjects):
for mobject in self.extract_mobject_family_members(mobjects):
if mobject in self.fixed_in_frame_mobjects:
self.fixed_in_frame_mobjects.remove(mobject)