Extension: omni.kit.manipulator.tool.snap-1.4.5 |
Documentation Generated: Jul 17, 2024 |
Usage Examples
Snap Object To Grid
import asyncio
import carb.settings
from omni.kit.manipulator.tool.snap.manager import SnapProviderManager
from omni.kit.manipulator.tool.snap.builtin_snap_tools import GRID_SNAP_NAME
from omni.kit.manipulator.tool.snap import settings_constants as c
from omni.kit.viewport.utility import get_active_viewport
from pxr import Gf
# Create and await an async method to perform snapping logic
async def snap_object_to_grid():
# Get the active viewport API for snapping
viewport_api = get_active_viewport()
# Create an instance of SnapProviderManager with the viewport API
snap_manager = SnapProviderManager(viewport_api=viewport_api)
# set the snap provider name to GRID_SNAP_NAME
settings = carb.settings.get_settings()
settings.set(c.SNAP_PROVIDER_NAME_SETTING_PATH, GRID_SNAP_NAME)
# Define a callback function to handle the snap results
def on_snap_result(position, keep_spacing):
print(f"Snapped position: {position}, Keep spacing: {keep_spacing}")
# Start snap operation
snap_manager.on_began(excluded_paths=[])
# Perform snapping to grid at the center of the viewport (NDC coordinates (0, 0))
snap_manager.get_snap_pos(
xform=Gf.Matrix4d(1.0), # Identity matrix for the object's current transform
ndc_location=(0, 0, 0), # NDC location at the center of the viewport
scene_view=None, # Scene view is not needed in this context
on_snapped=on_snap_result # The callback function to handle snap results
)
# End snap operation
snap_manager.on_ended()
# Run the async method
asyncio.ensure_future(snap_object_to_grid())
Implement a custom snap provider, Register and Unregister the snap provider
from typing import List, Sequence, Union, Callable
from omni.kit.manipulator.tool.snap import SnapProvider
from omni.kit.manipulator.tool.snap.registry import SnapProviderRegistry
import omni.kit.mesh.raycast
import omni.timeline
from pxr import Gf, Sdf, Usd
class MyPrimSnap(SnapProvider):
"""implement a customized prim snap provider that allows snapping objects to the closest primitive based on provided NDC position."""
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self._raycast = omni.kit.mesh.raycast.acquire_mesh_raycast_interface()
self._raycast_context = self._raycast.create_context()
self._timeline = omni.timeline.get_timeline_interface()
def destroy(self):
if self._raycast_context:
self._raycast.destroy_context(self._raycast_context)
self._raycast_context = None
def on_began(self, excluded_paths: List[Union[str, Sdf.Path]], **kwargs):
"""Initializes the snap operation with a list of paths to exclude from snapping."""
self._excluded_paths = excluded_paths
self._prev_refresh_rate = self._raycast.get_bvh_refresh_rate()
self._raycast.set_bvh_refresh_rate(omni.kit.mesh.raycast.BvhRefreshRate.FAST, True)
self._raycast.set_disallowed_mesh_paths(
[str(path) for path in self._excluded_paths], True, self._raycast_context
)
def on_ended(self, **kwargs):
"""Resets the state of the provider when the snap operation ends."""
self._excluded_paths = []
self._raycast.set_disallowed_mesh_paths([], True, self._raycast_context)
self._raycast.set_bvh_refresh_rate(self._prev_refresh_rate, True)
def _get_current_timecode(self) -> Usd.TimeCode:
return Usd.TimeCode(self._timeline.get_current_time() * self._timeline.get_time_codes_per_seconds())
def on_snap(
self,
xform: Gf.Matrix4d,
ndc_location: Sequence[float],
want_orient: bool,
want_keep_spacing: bool,
on_snapped: Callable,
*args,
**kwargs,
) -> bool:
"""Attempts to snap to the closest prim"""
# generate picking ray from ndc cursor location.
(origin, dir, dist) = self._generate_picking_ray(ndc_location)
# find the closest prim
result = self._raycast.closestRaycast(origin, dir, dist, self._raycast_context)
if result.meshIndex >= 0:
path = self._raycast.get_mesh_path_from_index(result.meshIndex)
if path:
payload = {}
payload["keep_spacing"] = want_keep_spacing
payload["path"] = path
transform = self._viewport_api.usd_context.compute_path_world_transform(path)
payload["position"] = (transform[12], transform[13], transform[14])
if want_orient:
rotation = Gf.Matrix3d(
transform[0],
transform[1],
transform[2],
transform[4],
transform[5],
transform[6],
transform[8],
transform[9],
transform[10],
)
rotation.Orthonormalize()
payload["orient"] = rotation.ExtractRotation()
on_snapped(**payload)
return True
return False
@staticmethod
def get_name() -> str:
"""Returns the unique name of this snap provider."""
return "My Prim (Mesh Based)"
@classmethod
def get_display_name(cls) -> str:
"""Returns the display name of this snap provider."""
return "My Prim"
@staticmethod
def can_orient() -> bool:
"""Indicates if this snap provider can orient objects."""
return True
# Get the singleton instance of SnapProviderRegistry
registry = SnapProviderRegistry.get_instance()
# Register a new MyPrimSnap provider
registry.register_provider(MyPrimSnap)
# Unregister the MyPrimSnap provider
registry.unregister_provider(MyPrimSnap)