Function build_frustum_mesh_geometries

benchmark/utils/visualization.py:146–193

Convert each camera's frustum line segments into thin-cylinder triangle meshes (one merged Mesh per camera). Compared to build_frustum_geometries() (which returns Path3D/LINES), triangle meshes render more reliably in tools like MeshLab and Blender and do not trigger crashes related to the

(extrinsics, intrinsics, image_size, scale=0.1, line_radius=None)

def build_frustum_mesh_geometries(extrinsics, intrinsics, image_size, scale=0.1, line_radius=None):
    """Convert each camera's frustum line segments into thin-cylinder triangle meshes (one merged Mesh per camera).

    Compared to build_frustum_geometries() (which returns Path3D/LINES), triangle meshes render
    more reliably in tools like MeshLab and Blender and do not trigger crashes related to the LINES primitive.

    Args:
        extrinsics: (N, 3, 4) cam2world
        intrinsics: (N, 3, 3) intrinsics
        image_size: (W, H) or (N, 2)
        scale: frustum size
        line_radius: cylinder radius (None = automatically use scale*0.015)

    Returns:
        list[trimesh.Trimesh] — one colored Mesh per camera
    """
    import trimesh

    N = len(extrinsics)
    if line_radius is None:
        line_radius = max(scale * 0.015, 0.001)

    geoms = []
    for i in range(N):
        if isinstance(image_size, (list, tuple)) and len(image_size) == 2 and not hasattr(image_size[0], '__len__'):
            W, H = image_size
        else:
            W, H = image_size[i]

        segs = camera_frustum_lines(intrinsics[i], extrinsics[i], W, H, scale)
        color = _camera_color(i, N)
        rgba = np.array([color[0], color[1], color[2], 255], dtype=np.uint8)

        cyls = []
        for seg in segs:
            cyl = _segment_to_cylinder(seg[0], seg[1], line_radius, sections=6)
            if cyl is None:
                continue
            cyl.visual.vertex_colors = np.tile(rgba, (len(cyl.vertices), 1))
            cyls.append(cyl)

        if not cyls:
            continue

        merged = trimesh.util.concatenate(cyls)
        geoms.append(merged)

    return geoms


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