include topo transform in ray check

CHANGELOG.md

@@ -65,6 +65,7 @@
 - `IndexedPolycurve` constructor that takes list of `BoundedCurve` now produces `CurveIndices` that share vertices and are withing index range. This means `IndexedPolyline.TransformedPolyline` preserves `CurveIndicies` on new `IndexedPolyline`.
 - `BoundedCurve.ToPolyline` now works correctly for `EllipticalArc` class.
 - `Ray.Intersects(Topography)` and `Ray.Intersects(Mesh)` would sometimes return a different intersection than the closest one.
+- `Ray.Intersects(Topography)` now considers the topography's transform.
 
 ### Changed
 

Elements/src/Geometry/Ray.cs

@@ -236,15 +236,23 @@ public bool Intersects(Plane plane, out Vector3 result, out double t)
         }
 
         /// <summary>
-        /// Does this ray intersect the provided topography? Note that the Topography's transform is not considered. 
+        /// Does this ray intersect the provided topography?
         /// </summary>
         /// <param name="topo">The topography.</param>
         /// <param name="result">The location of intersection.</param>
         /// <returns>True if an intersection result occurs.
         /// False if no intersection occurs.</returns>
         public bool Intersects(Topography topo, out Vector3 result)
         {
-            return Intersects(topo.Mesh, out result);
+            var transform = topo.Transform;
+            var inverse = transform.Inverted();
+            var transformedRay = new Ray(inverse.OfPoint(Origin), Direction);
+            var intersects = transformedRay.Intersects(topo.Mesh, out result);
+            if (intersects)
+            {
+                result = transform.OfPoint(result);
+            }
+            return intersects;
         }
 
         /// <summary>

Elements/test/RayTests.cs

@@ -7,6 +7,8 @@
 using Xunit.Abstractions;
 using System.Diagnostics;
 using Vertex = Elements.Geometry.Vertex;
+using Xunit.Sdk;
+using System.Linq;
 
 namespace Elements.Tests
 {
@@ -74,23 +76,23 @@ public void RayIntersectsTopography()
                     e++;
                 }
             }
-            var topo = new Topography(Vector3.Origin, 10, elevations);
-            topo.Material = new Material("topo", new Color(0.5, 0.5, 0.5, 0.5));
+            var topo = new Topography(Vector3.Origin, 10, elevations)
+            {
+                Material = new Material("topo", new Color(0.5, 0.5, 0.5, 0.5)),
+                Transform = new Transform(0, 0, 2)
+            };
             this.Model.AddElement(topo);
-
-            var ray = new Ray(Vector3.Origin, Vector3.ZAxis);
-            this.Model.AddElement(ModelCurveFromRay(ray));
-            Assert.True(ray.Intersects(topo.Mesh, out var result));
+            this.Model.AddElements(new Transform().ToModelCurves());
             for (int i = 1; i < 9; i++)
             {
                 for (int j = 1; j < 9; j++)
                 {
                     var newRay = new Ray(new Vector3(i, j, 40), Vector3.ZAxis.Negate());
-                    var intersect = newRay.Intersects(topo.Mesh, out var result2);
+                    var intersect = newRay.Intersects(topo, out var result2);
                     Assert.True(intersect);
                     var line = new Line(result2, newRay.Origin);
                     Model.AddElement(new ModelCurve(line, BuiltInMaterials.XAxis));
-                    Assert.True(result2.Z > 0 && result2.Z < 40);
+                    Assert.True(result2.Z > elevations.Min() + 2 && result2.Z < elevations.Max() + 2);
                 }
             }
         }