Houdini Point Cloud Decorator for Level I/O (asset: transformation)

HoudiniPointCloud.py

# DevUtils
# ===========================
from DevUtils.OSP.PointCloudMarkup import PointCloud, PointInstance

# Houdini
# ===========================
from HoudiniUtils.Math.HoudiniMatrix4d import HoudiniMatrix4d

# 3rd Party
# ===========================
import hou

import os

class HoudiniPointCloud(object):
    """
    Houdini wrapper for PointCloud to read or write from hou.Geometry.

    Args:
        pointCloud (PointCloud): the PointCloud instance we are decorating.
    """
    def __init__(self, pointCloud):
        self._pointCloud = pointCloud

    # This object _is_ a PointCloud
    def __getattr__(self, item):
        if hasattr(self._pointCloud, item):
            return getattr(self._pointCloud, item)

        raise AttributeError("[{}] is missing from backing PointCloud!".format(item))

    @classmethod
    def FromGeometry(cls, pointCloud, geometry):
        """
        Convenience constructor to create a HoudiniPointCloud from data on hou.Geometry.

        Args:
            pointCloud (PointCloud): The backing PointCloud instance.
            geometry (hou.Geometry): The geometry we will read point data from.

        Returns:
            (HoudiniPointCloud): HoudiniPointCloud build from geometry points and their attributes.
        """
        houdiniPointCloud = cls(pointCloud)
        points = geometry.points()
        for point in points:
            path = point.attribValue("path")
            matrix = HoudiniMatrix4d.FromPointAttributs(point)
            matrix.convert()

            pointInstance = PointInstance(path, matrix.asArrayString())
            houdiniPointCloud.add(pointInstance)

        return houdiniPointCloud

    def toGeometry(self, geometry):
        """
        Write this PointCloud to points on the provided hou.Geometry.

        Returns:
            geometry (hou.Geometry): geometry populated with PointCloud data.
        """
        if geometry.findPointAttrib("orient") is None:
            geometry.addAttrib(hou.attribType.Point, "orient", (1.0, 1.0, 1.0, 1.0))
        if geometry.findPointAttrib("scale") is None:
            geometry.addAttrib(hou.attribType.Point, "scale", (1.0, 1.0, 1.0))
        if geometry.findPointAttrib("path") is None:
            geometry.addAttrib(hou.attribType.Point, "path", "")

        for instance in self.instances():
            point = geometry.createPoint()

            matrix = HoudiniMatrix4d(instance.matrix4d())
            matrix.convert()
            matrix.toPointAttributes(point)

            # For full path access in VEX--important for setprimintrinsic
            main = hou.getenv("ROOT")
            path = "{}/{}".format(main, instance.path())
            path = os.path.normpath(path).replace("\\", "/")

            point.setAttribValue("path", path)

        return geometry