import bpy
from .utils import project_points
import mathutils
import numpy as np
from ..blender.mesh import Mesh
from ..blender.camera import Camera
from .annotation_handler import AnnotationHandler
from typing import List, Union
BBOX_FMTS = ["x1y1x2y2", "xywh"]
def _bounding_box(
object: Mesh,
camera: bpy.types.Camera = None,
scene: bpy.types.Scene = None,
return_fmt: str = "x1y1x2y2",
normalized: bool = False,
invert_y: bool = True,
) -> tuple:
"""Get the bounding box of an object in camera space.
Achieve this by projecting all vertices of the object to the image plane,
and taking the min/max of the resulting coordinates.
:param object: Mesh
:param camera: bpy.types.Camera (if None, use bpy.context.scene.camera)
:param scene: bpy.types.Scene (if None, use bpy.context.scene)
:param return_fmt: one of ['x1y1x2y2', 'xywh']
:param normalized: if True, return normalized coordinates (0-1) instead of pixel coordinates
:param invert_y: if True, y is measured from the top of the image, otherwise from the bottom (Blender measures from bottom)
"""
if camera is None:
camera = bpy.context.scene.camera
if scene is None:
scene = bpy.context.scene
verts = object._get_all_vertices("WORLD")
coords_2d = project_points(verts, scene, camera, invert_y=invert_y)
if normalized:
coords_2d[:, 0] /= scene.render.resolution_x
coords_2d[:, 1] /= scene.render.resolution_y
xmin, ymin = coords_2d.min(axis=0)
xmax, ymax = coords_2d.max(axis=0)
if return_fmt == "x1y1x2y2":
return xmin, ymin, xmax, ymax
elif return_fmt == "xywh":
return xmin, ymin, xmax - xmin, ymax - ymin
else:
raise ValueError(
f"Invalid return_fmt: {return_fmt}. Must be one of {BBOX_FMTS}"
)
def _bounding_boxes(
objects: List[Mesh],
camera: bpy.types.Camera = None,
scene: bpy.types.Scene = None,
return_fmt: str = "x1y1x2y2",
normalized: bool = False,
invert_y: bool = True,
) -> List[tuple]:
"""Run `bounding_box` for multiple objects
:param objects: List of Mesh objects
:param camera: bpy.types.Camera (if None, use bpy.context.scene.camera)
:param scene: bpy.types.Scene (if None, use bpy.context.scene)
:param return_fmt: one of ['x1y1x2y2', 'xywh']
:param normalized: if True, return normalized coordinates (0-1) instead of pixel coordinates
:param invert_y: if True, y is measured from the top of the image, otherwise from the bottom (Blender measures from bottom)
"""
return [
_bounding_box(
obj,
camera=camera,
scene=scene,
return_fmt=return_fmt,
normalized=normalized,
invert_y=invert_y,
)
for obj in objects
]
[docs]
def bounding_boxes(
objects: List[Mesh],
camera: Union[Camera, List[Camera]] = None,
scene: bpy.types.Scene = None,
return_fmt: str = "x1y1x2y2",
normalized: bool = False,
invert_y: bool = True,
) -> AnnotationHandler:
"""
Project bounding boxes of all objects in list to all cameras provided.
:param objects: List of Mesh objects
:param camera: Either a single :class:`~blendersynth.blender.camera.Camera` object, or a list of them. If None, use bpy.context.scene.camera
:param scene: bpy.types.Scene (if None, use bpy.context.scene)
:param return_fmt: one of ['x1y1x2y2', 'xywh']
:param normalized: if True, return normalized coordinates (0-1) instead of pixel coordinates
:param invert_y: if True, y is measured from the top of the image, otherwise from the bottom (Blender measures from bottom)
"""
return_dict = {}
if camera is None:
camera = bpy.context.scene.camera
if not isinstance(camera, list):
camera = [camera]
for cam in camera:
return_dict[cam.name] = _bounding_boxes(
objects,
camera=cam,
scene=scene,
return_fmt=return_fmt,
normalized=normalized,
invert_y=invert_y,
)
return AnnotationHandler.from_annotations(return_dict, ann_type="bbox")