open3D 05

[신민서]

05. Geometry

Open3D 좌표의 단위는 무엇인가?

float64 array of shape (num_points, 3)

x, y, z

https://www.open3d.org/docs/release/python_api/open3d.utility.Vector3dVector.html#open3d.utility.Vector3dVector

open3d.utility.Vector3dVector - Open3D 0.19.0 documentation

Open3D 각도의 단위는 무엇인가?

numpy.float64

라디안 단위로 각도 계산에 들어감

https://www.open3d.org/docs/release/python_api/open3d.geometry.AxisAlignedBoundingBox.html#open3d.geometry.AxisAlignedBoundingBox.get_rotation_matrix_from_axis_angle

open3d.geometry.AxisAlignedBoundingBox - Open3D 0.19.0 documentation

Open3D 컬러를 정의하는 방법은?

float64 array of shape (num_lines, 3), range [0, 1]

0과 1사이의 값을 얻으며 1이 255, 0이 0값이라고 보면 됨

RGB colors of lines Open3d color > (r, g, b), 0~1범위의 실수

Open3D.geometry.TriangleMesh.create_box의 width, height, depth의 정의를 설명하시오.
각 인자의 축의 방향을 설명하시오.

• width: float형, 디폴트 값으로 1.0이 들어가있음, x축 방향의 길이를 나타냄
• height: float형, 디폴트 값으로 1.0이 들어가있음, y축 방향의 길이를 나타냄
• depth: float형, 디폴트 값으로 1.0이 들어가있음, z축 방향의 길이를 나타냄

https://www.open3d.org/docs/release/python_api/open3d.geometry.TriangleMesh.html

open3d.geometry.TriangleMesh - Open3D 0.19.0 documentation

Open3d 바운딩 박스의 length, width, height의 정의는 무엇인가?

• length: x축 방향
• width: y축 방향 
• height: z축 방향

Create OrientedBoudingBox from center, rotation R and extent in x, y and z direction

중심점 (x, y, z) 기준으로 length, width, height 범위만큼 바운딩 박스 생성함

과제: LineSet

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import open3d as o3d import numpy as np   points = [] lines = [] colors = []   # 격자 설정 gap = 0.2 # 한 칸 간격 num_lines = 11  # 0~10까지 half_range = 1 # -1부터 1까지의 좌표 범위   # Z 방향으로 X축 선 (빨간색) for i in range(num_lines):     z = -half_range + i * gap # -1~1 범위에서 gap 간격으로 이동     points.append([-half_range, 0, z]) # 좌표 append     points.append([half_range, 0, z])     idx = len(points)     lines.append([idx - 2, idx - 1]) # 두 점 연결     colors.append([1, 0, 0])  # red   # X 방향으로 Z축 선 (파란색) for i in range(num_lines):     x = -half_range + i * gap     points.append([x, 0, -half_range])     points.append([x, 0, half_range])     idx = len(points)     lines.append([idx - 2, idx - 1])     colors.append([0, 0, 1])  # blue     line_set = o3d.geometry.LineSet() line_set.points = o3d.utility.Vector3dVector(points) line_set.lines = o3d.utility.Vector2iVector(lines) line_set.colors = o3d.utility.Vector3dVector(colors)   axis_frame = o3d.geometry.TriangleMesh.create_coordinate_frame(size=1) o3d.visualization.draw_geometries([line_set, axis_frame], width=500, height=500)   Colored by Color Scripter

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과제: TriangleMesh

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import open3d as o3d import numpy as np   mesh_sphere1 = o3d.geometry.TriangleMesh.create_sphere(radius=1.0) mesh_sphere1.translate([2,0,0]) mesh_sphere1.compute_vertex_normals() mesh_sphere1.paint_uniform_color([0.1, 0.1, 0.7])   mesh_box = o3d.geometry.TriangleMesh.create_box(width=1.0,height=1.0,depth=1.0) mesh_box.translate([3,0,0]) mesh_box.compute_vertex_normals() mesh_box.paint_uniform_color([0.9, 0.1, 0.1])   mesh_sphere2 = o3d.geometry.TriangleMesh.create_sphere(radius=1.0) mesh_sphere2.translate([5,0,0]) mesh_sphere2.compute_vertex_normals() mesh_sphere2.paint_uniform_color([0.1, 0.1, 0.7])   min_bound = np.array([1.0, -1.0, -1.0]) max_bound = np.array([6.0, 1.0, 1.0])   aabb = o3d.geometry.AxisAlignedBoundingBox(min_bound=min_bound, max_bound=max_bound) aabb.color = (1, 0, 0) # 빨간색   mesh_frame = o3d.geometry.TriangleMesh.create_coordinate_frame(size=1, origin=[0, 0, 0]) o3d.visualization.draw_geometries([aabb, mesh_box, mesh_sphere1, mesh_sphere2, mesh_frame],width=500,height=500)

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과제: AxisAlignedBoundingBox

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import open3d as o3d import numpy as np   # AABB 경계 설정 min_bound = np.array([0.0, 0.0, 0.0]) max_bound = np.array([1.0, 2.0, 3.0])   # AABB 생성 및 색상 aabb = o3d.geometry.AxisAlignedBoundingBox(min_bound, max_bound) aabb.color = (0, 0, 0)   points = np.array(aabb.get_box_points())   lines = [     [0, 7],     [1, 2],     [3, 4],     [5, 6], ] colors = [[1, 0, 0]] * 4  # 빨간색 4개   diagonals = o3d.geometry.LineSet() diagonals.points = o3d.utility.Vector3dVector(points) diagonals.lines = o3d.utility.Vector2iVector(lines) diagonals.colors = o3d.utility.Vector3dVector(colors)   axis_frame = o3d.geometry.TriangleMesh.create_coordinate_frame(size=0.5)   o3d.visualization.draw_geometries([aabb, diagonals, axis_frame], width=500, height=500)   Colored by Color Scripter

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과제: OrientedBoundingBox

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import open3d as o3d import numpy as np     # 모든 center point를 0, 0, 0으로 설정 center = np.array([0, 0, 0]) axis_angles = np.array([0, 0, 0])   rotation = o3d.geometry.get_rotation_matrix_from_axis_angle(axis_angles) extent = np.array([1, 1, 1])   obb = o3d.geometry.OrientedBoundingBox(center, rotation, extent) obb.color = [1, 0, 0]   points = np.array(obb.get_box_points())   lines = [     [0, 7],     [1, 2],     [3, 4],     [5, 6], ] colors = [[1, 0, 0]] * 4  # 빨간색 4개   diagonals = o3d.geometry.LineSet() diagonals.points = o3d.utility.Vector3dVector(points) diagonals.lines = o3d.utility.Vector2iVector(lines) diagonals.colors = o3d.utility.Vector3dVector(colors)   axis_frame = o3d.geometry.TriangleMesh.create_coordinate_frame(size=0.5, origin=[0, 0, 0]) o3d.visualization.draw_geometries([obb, diagonals, axis_frame], width=500, height=500)

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과제: Crop PointCloud

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import open3d as o3d import numpy as np   pcd= o3d.geometry.PointCloud() np_points= np.random.rand(100, 3) pcd.points= o3d.utility.Vector3dVector(np_points)   aabb1 = pcd.get_axis_aligned_bounding_box() aabb1.color= [1, 0, 0]    y_center = aabb1.get_center()[1]  # [x_center, y_center, z_center]를 반환함 y기준만 쓸거니까 [1] 꺼내서 씀   filtered_points = [] for point in np_points:     if point[1] <= y_center:         filtered_points.append(point) filtered_points = np.array(filtered_points)   filtered_pcd = o3d.geometry.PointCloud() filtered_pcd.points = o3d.utility.Vector3dVector(filtered_points)   aabb2 = filtered_pcd.get_axis_aligned_bounding_box() aabb2.color = [0, 1, 0]    axis_frame= o3d.geometry.TriangleMesh.create_coordinate_frame(size=0.5, origin=[0, 0, 0]) o3d.visualization.draw_geometries([filtered_pcd  ,axis_frame,aabb1, aabb2], width=500,height=500)

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과제: Project PointCloud

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import open3d as o3d import numpy as np   pcd = o3d.geometry.PointCloud() np_points = np.random.rand(100, 3)   np_points[:, 0] = 0 # np_points[:, 1] = 0 # np_points[:, 2] = 0   pcd.points = o3d.utility.Vector3dVector(np_points)     axis_frame = o3d.geometry.TriangleMesh.create_coordinate_frame(size=0.5, origin=[0, 0, 0]) o3d.visualization.draw_geometries([pcd, axis_frame], width=500,height=500)

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