warp.pnoise
===========

.. function:: warp._src.lang.pnoise(state: uint32, x: float32, px: int32) -> float

   .. hlist::
      :columns: 8

      * Kernel
      * Python
      * Differentiable

   Sample 1D Perlin noise that repeats with an integer period.
   
   Wraps the :func:`noise` lattice every ``px`` cells, with one cell per input unit.
   ``state`` selects the field and is not advanced. Values have the same scale and
   determinism behavior as :func:`noise`.
   
   Period arguments must be positive. Negative coordinates are currently unsupported.
   The field is differentiable with respect to coordinates. Period arguments receive
   no Warp autodiff gradient.
   
   :param state: RNG state that selects the noise field (see :func:`rand_init`); never advanced.
   :param x: Coordinate to sample. One noise feature spans one unit.
   :param px: Period along x, in units. ``px`` must be greater than zero.
   
   :returns: The noise value at ``x``.
   
   .. rubric:: Example
   
   .. testcode::
   
       @wp.kernel
       def sample_periodic_noise(seed: int, coords: wp.array[float], values: wp.array[float]):
           tid = wp.tid()
           state = wp.rand_init(seed)
           values[tid] = wp.pnoise(state, coords[tid], 4)
   
       # a point, then the same point shifted by one and by two periods
       coords = wp.array([0.75, 4.75, 8.75], dtype=float)
       values = wp.zeros(len(coords), dtype=float)
   
       wp.launch(sample_periodic_noise, dim=len(coords), inputs=[42, coords], outputs=[values])
       print(np.allclose(values.numpy(), values.numpy()[0]))
   
   .. testoutput::
   
       True
   

.. function:: warp._src.lang.pnoise(state: uint32, xy: vec2f, px: int32, py: int32) -> float
   :noindex:

   .. hlist::
      :columns: 8

      * Kernel
      * Python
      * Differentiable

   Sample 2D Perlin noise that repeats with an integer period.
   
   See :func:`pnoise` for shared behavior, restrictions, and a usage example.
   
   :param state: RNG state that selects the noise field (see :func:`rand_init`); never advanced.
   :param xy: Coordinate to sample. One noise feature spans one unit.
   :param px: Period along x, in units. ``px`` must be greater than zero.
   :param py: Period along y, in units. ``py`` must be greater than zero.
   
   :returns: The noise value at ``xy``.
   

.. function:: warp._src.lang.pnoise(state: uint32, xyz: vec3f, px: int32, py: int32, pz: int32) -> float
   :noindex:

   .. hlist::
      :columns: 8

      * Kernel
      * Python
      * Differentiable

   Sample 3D Perlin noise that repeats with an integer period.
   
   See :func:`pnoise` for shared behavior, restrictions, and a usage example.
   
   :param state: RNG state that selects the noise field (see :func:`rand_init`); never advanced.
   :param xyz: Coordinate to sample. One noise feature spans one unit.
   :param px: Period along x, in units. ``px`` must be greater than zero.
   :param py: Period along y, in units. ``py`` must be greater than zero.
   :param pz: Period along z, in units. ``pz`` must be greater than zero.
   
   :returns: The noise value at ``xyz``.
   

.. function:: warp._src.lang.pnoise(state: uint32, xyzt: vec4f, px: int32, py: int32, pz: int32, pt: int32) -> float
   :noindex:

   .. hlist::
      :columns: 8

      * Kernel
      * Python
      * Differentiable

   Sample 4D Perlin noise that repeats with an integer period.
   
   The fourth coordinate is commonly used as looping time. See :func:`pnoise` for
   shared behavior, restrictions, and a usage example.
   
   :param state: RNG state that selects the noise field (see :func:`rand_init`); never advanced.
   :param xyzt: Coordinate to sample. One noise feature spans one unit.
   :param px: Period along x, in units. ``px`` must be greater than zero.
   :param py: Period along y, in units. ``py`` must be greater than zero.
   :param pz: Period along z, in units. ``pz`` must be greater than zero.
   :param pt: Period along the fourth axis, in units. ``pt`` must be greater than zero.
   
   :returns: The noise value at ``xyzt``.