fix(plane): Add method to project points onto planes

ladybug_geometry/geometry3d/plane.py

@@ -4,8 +4,9 @@
 
 from .pointvector import Point3D, Vector3D
 from .ray import Ray3D
-from ..intersection3d import intersect_line3d_plane, intersect_plane_plane, \
-    closest_point3d_on_plane, closest_point3d_between_line3d_plane
+from ..intersection3d import intersect_line3d_plane, intersect_line3d_plane_infinite, \
+    intersect_plane_plane, closest_point3d_on_plane, \
+    closest_point3d_between_line3d_plane
 from ..geometry2d.pointvector import Point2D, Vector2D
 from ..geometry2d.ray import Ray2D
 
@@ -319,6 +320,23 @@ def distance_to_line(self, line_ray):
         else:
             return result[0].distance_to_point(result[1])
 
+    def project_point(self, point, projection_direction=None):
+        """Project a point onto this Plane given a certain projection direction.
+
+        Args:
+            point: A Point3D to be projected onto the plane
+            projection_direction: A Line3D or Ray3D object to set the direction
+                of projection. If None, this Plane's normal will be
+                used. (Default: None).
+
+        Returns:
+            Point3D for the projected point. Will be None if the projection_direction
+            is parallel to the plane.
+        """
+        int_ray = Ray3D(point, self.n) if projection_direction is None \
+            else Ray3D(point, projection_direction)
+        return intersect_line3d_plane_infinite(int_ray, self)
+
     def intersect_line_ray(self, line_ray):
         """Get the intersection between this plane and the input Line3D or Ray3D.
 

ladybug_geometry/intersection3d.py

@@ -15,7 +15,7 @@ def intersect_line3d_plane(line_ray, plane):
         plane: A Plane object to intersect.
 
     Returns:
-        Point2D of intersection if it exists. None if no intersection exists.
+        Point3D of intersection if it exists. None if no intersection exists.
     """
     d = plane.n.dot(line_ray.v)
     if not d:  # parallel
@@ -28,6 +28,26 @@ def intersect_line3d_plane(line_ray, plane):
                    line_ray.p.z + u * line_ray.v.z)
 
 
+def intersect_line3d_plane_infinite(line_ray, plane):
+    """Get the intersection between a Plane and Ray2D/LineSegment2D extended infinitely.
+
+    Args:
+        line_ray: ALineSegment2D or Ray2D that will be extended infinitely
+            for intersection.
+        plane: A Plane object to intersect.
+
+    Returns:
+        Point3D of intersection if it exists. None if no intersection exists.
+    """
+    d = plane.n.dot(line_ray.v)
+    if not d:  # parallel
+        return None
+    u = (plane.k - plane.n.dot(line_ray.p)) / d
+    return Point3D(line_ray.p.x + u * line_ray.v.x,
+                   line_ray.p.y + u * line_ray.v.y,
+                   line_ray.p.z + u * line_ray.v.z)
+
+
 def intersect_plane_plane(plane_a, plane_b):
     """Get the intersection between two Plane objects.