Skip to content

compas_nest.viewer

compas_nest.viewer

Optional compas_viewer helper for the live animation (requires pip install compas_viewer).

animate drives a running solve in a top (plan) view fitted to the geometry, groups sheets and elements (with their holes), and optionally writes the final layout to COMPAS JSON.

animate(handle, geo, sheets, save=None, park=-80.0)

Animate a running solve live (top view); save the final layout to save on close.

Parameters:

Name Type Description Default
handle :class:`compas_nest.collision_solve` or :class:`compas_nest.nfp_solve`

What :meth:compas_nest.opennest_collision.start or :meth:compas_nest.opennest.start returns.

 required
geo :class:`compas_nest.nest_geo`

The parts to draw/save (one viewer object per instance). May differ from the geometry the handle solved — e.g. pass the original parts while the solve ran on offset geometry, to show the true parts with the resulting gaps (same part order/copies required).

 required
sheets :class:`compas_nest.nest_sheets`

The sheets being nested into.

 required
save str

If given, the final layout is written to this JSON path when the window closes.

 None
park float

Y offset where not-yet-placed elements are staged (below the sheets).

 -80.0
Source code in compas_nest/viewer.py 
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
def animate(
    handle: Union[collision_solve, nfp_solve],
    geo: nest_geo,
    sheets: nest_sheets,
    save: Optional[str] = None,
    park: float = -80.0,
) -> None:
    """Animate a running solve live (top view); save the final layout to ``save`` on close.

    Parameters
    ----------
    handle : :class:`compas_nest.collision_solve` or :class:`compas_nest.nfp_solve`
        What :meth:`compas_nest.opennest_collision.start` or :meth:`compas_nest.opennest.start` returns.
    geo : :class:`compas_nest.nest_geo`
        The parts to draw/save (one viewer object per instance). May differ from the geometry the
        ``handle`` solved — e.g. pass the *original* parts while the solve ran on offset geometry,
        to show the true parts with the resulting gaps (same part order/copies required).
    sheets : :class:`compas_nest.nest_sheets`
        The sheets being nested into.
    save : str, optional
        If given, the final layout is written to this JSON path when the window closes.
    park : float, optional
        Y offset where not-yet-placed elements are staged (below the sheets).
    """
    from compas_viewer import Viewer

    viewer = Viewer()
    _add_sheets(viewer, sheets)

    # one object per part instance, created from the original geometry; only its transform changes
    instances = [(i, part) for i, part in enumerate(geo.parts) for _ in range(max(1, int(part["copies"])))]
    group = viewer.scene.add_group(name="elements")
    objects = []
    for k, (part_index, part) in enumerate(instances):
        sub = viewer.scene.add_group(name="element_%d" % k, parent=group)
        objects.append([sub.add(part["outline"], linecolor=ELEMENT_COLOR, linewidth=2)] + [sub.add(h, linecolor=ELEMENT_COLOR) for h in part["holes"]])

    parked = Translation.from_vector([0.0, park, 0.0])

    @viewer.on(interval=120)
    def _(frame):
        running = handle.is_running()
        layout = handle.snapshot() if running else handle.wait()  # final layout once the solve ends
        viewer.renderer.makeCurrent()
        for k, parts in enumerate(objects):
            placement = layout.placements[k]
            matrix = layout.transformation(placement) if placement["sheet_id"] >= 0 else parked
            for obj in parts:
                obj.transformation = matrix
                obj.update(update_transform=True)
        viewer.renderer.doneCurrent()
        if frame == 0:
            _fit_top(viewer)
        if not running:
            viewer.timer.stop()

    viewer.show()
    handle.cancel()
    if save:
        import os

        result = handle.wait()
        result.geo = geo  # render/serialize the geometry passed here (e.g. the original parts when solving on offset geometry)
        result.to_json(save)
        result.to_obj(os.path.splitext(os.fspath(save))[0] + ".obj")