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import trimesh
import json
import numpy as np
PI = np.pi
# 可以是标量（各向同性）或三元组（各向异性）
# 例如：1.0 或 [0.08, 0.4, 0.08]
MODEL_SCALE = 0.004
GRASP_OFFSET = [0., 0., 0.] # 相对“顶部中心”的偏移
GRASP_ROT = [PI, 0.0, PI] # 欧拉角 (rx, ry, rz), 弧度
def _to_scale_vec(scale):
"""将标量/数组统一成 3 维缩放向量 [sx, sy, sz]."""
arr = np.asarray(scale, dtype=float)
if arr.ndim == 0:
return [float(arr)] * 3
if arr.shape == (3,):
return arr.tolist()
raise ValueError(f"MODEL_SCALE 需为标量或长度为3的向量，收到形状: {arr.shape}")
def create_model_data(id="vase"):
file_path = f"./{id}.glb"
save_path = f"./model_data.json"
# 1) 读模型并融合为单一 Trimesh
with open(file_path, "rb") as f:
loaded = trimesh.load(f, file_type="glb")
mesh = loaded.to_mesh() if isinstance(loaded, trimesh.Scene) else loaded
# 2) 应用缩放（标量或三元向量都可）
scale_vec = _to_scale_vec(MODEL_SCALE)
mesh.apply_scale(scale_vec) # 支持 float 或 (3,) 向量
# 3) OBB 信息
obb = mesh.bounding_box_oriented
center = obb.centroid
ext = obb.extents
diag = np.linalg.norm(ext)
# 4) 计算“底部中心” -> 原点的平移
rotation_matrix = obb.transform[:3, :3]
bottom_center = center - rotation_matrix[:, 2] * (ext[2] / 2.0)
mesh.apply_translation(-bottom_center)
# 5) 更新 OBB
obb = mesh.bounding_box_oriented
center = obb.centroid
ext = obb.extents
rotation_matrix = obb.transform[:3, :3]
# 6) 顶部中心（现在模型底部已对齐原点，Z 轴正向为“上”）
top_center = center + rotation_matrix[:, 2] * (ext[2] / 2.0)
# 7) 组合抓取位姿：先平移到顶部中心 -> 旋转 -> 偏移
grasp_translation = trimesh.transformations.translation_matrix(top_center)
grasp_rotation = trimesh.transformations.euler_matrix(*GRASP_ROT)
grasp_offset = trimesh.transformations.translation_matrix(GRASP_OFFSET)
grasp_transform = grasp_translation @ grasp_rotation @ grasp_offset
# 8) 可视化
scene = trimesh.Scene(mesh)
grasp_sphere = trimesh.creation.icosphere(subdivisions=2, radius=diag * 0.05)
grasp_sphere.apply_transform(grasp_transform)
grasp_sphere.visual.vertex_colors = np.array([[1.0, 0.0, 0.0, 0.5]] * len(grasp_sphere.vertices))
scene.add_geometry(grasp_sphere)
grasp_axis = trimesh.creation.axis(origin_size=0.05, axis_length=diag * 0.2)
grasp_axis.apply_transform(grasp_transform)
scene.add_geometry(grasp_axis)
# 9) 保存 JSON（注意 scale 为三元向量）
data = {
"center": center.tolist(),
"extents": ext.tolist(),
"scale": scale_vec,
"contact_points_pose": [grasp_transform.tolist()],
"transform_matrix": trimesh.transformations.identity_matrix().tolist(),
"functional_matrix": [],
"orientation_point": grasp_transform.tolist(),
"contact_points_group": [],
"contact_points_mask": [],
"contact_points_discription": [],
"target_point_discription": ["Grasp pose at the top edge center."],
"functional_point_discription": [""],
"orientation_point_discription": ["Grasp pose with adjustable offset and rotation."]
}
with open(save_path, "w", encoding="utf-8") as f:
json.dump(data, f, indent=4, ensure_ascii=False, separators=(",", ": "))
# 10) 显示场景
scene.show()
if __name__ == "__main__":
create_model_data("vase")
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