141 lines
4.6 KiB
Python
141 lines
4.6 KiB
Python
import direct
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import direct.showbase
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import direct.showbase.ShowBaseGlobal
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from panda3d.core import (
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Geom,
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GeomLines,
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GeomNode,
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GeomVertexData,
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GeomVertexFormat,
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GeomVertexWriter,
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LColor,
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LPoint3,
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NodePath
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)
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import panda3d.core as p3d
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class CornerBBox:
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def __init__(
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self,
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target: NodePath,
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color: tuple = (0.5, 0, 0.5, 1),
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corner_offset: float = 0.52,
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stub_scale: float = 0.075,
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line_thickness: float = 2.0,
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parent: NodePath | None = None
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) -> None:
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"""
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创建一个“角点风格”的包围盒可视化框。
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:param target: 要描框的 NodePath
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:param color: 线颜色 (r, g, b, a)
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:param corner_offset: 角点在包围盒外扩的偏移，决定框外伸出的长度
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:param stub_scale: 每个角三条小线的比例（实际使用两段：stub 和 3*stub + stub）
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:param line_thickness: 线粗细
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:param parent: 框的挂载节点，默认与 target 同级父节点
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"""
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self.world = direct.showbase.ShowBaseGlobal.base
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self.target = target
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self.parent = parent or target
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self.color = LColor(*color)
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self.corner_offset = corner_offset
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self.stub_scale = stub_scale
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self.line_thickness = line_thickness
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self.np = self._build_geom()
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self.update() # 初始化尺寸/位置
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def _build_geom(self) -> NodePath:
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"""构造“八角+三向短线”几何体"""
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fmt = GeomVertexFormat.get_v3c4()
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vdata = GeomVertexData("corner_bbox", fmt, Geom.UH_static)
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pos_w = GeomVertexWriter(vdata, "vertex")
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col_w = GeomVertexWriter(vdata, "color")
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lines = GeomLines(Geom.UH_static)
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# 定义 8 个角（基于偏移量 m）
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m = self.corner_offset
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corners = [(x, y, z) for x in (-m, m) for y in (-m, m) for z in (-m, m)]
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for corner in corners:
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cx, cy, cz = corner
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for axis_idx, coord in enumerate((cx, cy, cz)):
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sign = -1.0 if coord > 0 else 1.0
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# 两段短线：长度分别为 stub_scale 和 3 * stub_scale
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offset1 = self.stub_scale * sign
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offset2 = (3.0 * self.stub_scale + self.stub_scale) * sign
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base = list(corner)
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# 第一段线：从角点到第一个 stub
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p1 = LPoint3(*base)
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pos_w.add_data3(p1)
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col_w.add_data4(self.color)
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base[axis_idx] = coord + offset1
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p2 = LPoint3(*base)
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pos_w.add_data3(p2)
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col_w.add_data4(self.color)
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lines.add_next_vertices(2)
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# 第二段线：从第一个 stub 到更远的 stub
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base[axis_idx] = coord + offset2
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p3 = LPoint3(*base)
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pos_w.add_data3(p2) # 重复起点
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col_w.add_data4(self.color)
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pos_w.add_data3(p3)
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col_w.add_data4(self.color)
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lines.add_next_vertices(2)
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geom = Geom(vdata)
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geom.add_primitive(lines)
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node = GeomNode("corner_bbox")
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node.add_geom(geom)
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np = self.parent.attach_new_node(node)
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# 渲染设置
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np.set_light_off()
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np.set_texture_off()
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np.set_color_off(False) # 保留顶点色
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np.set_render_mode_thickness(self.line_thickness)
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mat = p3d.Material('unlit')
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np.setMaterial(mat)
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return np
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def update(self) -> None:
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"""根据 target 的 tight bounds 更新包围框的位置/缩放。"""
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if not self.world or self.target.is_empty() or self.np is None:
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return
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render = self.world.render
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# 统一在 render 坐标系下保存/恢复
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last_hpr = self.target.getHpr(render)
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try:
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# 暂时归零朝向
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self.target.setHpr(render, 0, 0, 0)
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bmin, bmax = self.target.get_tight_bounds(render)
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if not bmin or not bmax:
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return
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size = bmax - bmin
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center = (bmin + bmax) * 0.5
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# bbox 挂在 parent 下，但变换以 render 为参照设置，避免坐标系错乱
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self.np.set_pos(render, center)
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self.np.set_scale(render, size)
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finally:
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# 无论成功与否都必须恢复 target 姿态
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self.target.setHpr(render, last_hpr)
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def remove(self) -> None:
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"""从场景图中移除该包围框。"""
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if self.np is None:
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return
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self.np.detach_node()
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self.np = None |