basic reprojection for Remesher. Works OK, however edges w/ 2 fixed verts cannot be collapsed, which causes some weirdness w/ no normal-flip check...

Author: rms80

geometry3Sharp.csproj

@@ -146,6 +146,8 @@
     <Compile Include="intersection\IntrSegment3Box3.cs" />
     <Compile Include="intersection\IntrRay3Box3.cs" />
     <Compile Include="spatial\DMeshAABBTree.cs" />
+    <Compile Include="spatial\MeshProjectionTarget.cs" />
+    <Compile Include="spatial\SpatialInterfaces.cs" />
   </ItemGroup>
   <ItemGroup>
     <Folder Include="interfaces\" />

mesh/Remesher.cs

@@ -7,7 +7,7 @@ public class Remesher {
 
 		DMesh3 mesh;
         MeshConstraints constraints = null;
-
+        IProjectionTarget target = null;
 
 		public bool EnableFlips = true;
 		public bool EnableCollapses = true;
@@ -37,6 +37,11 @@ public void SetExternalConstraints(MeshConstraints cons)
         }
 
 
+        public void SetProjectionTarget(IProjectionTarget target)
+        {
+            this.target = target;
+        }
+
 
 		public void BasicRemeshPass() {
 
@@ -51,6 +56,9 @@ public void BasicRemeshPass() {
 
 			if ( EnableSmoothing && SmoothSpeedT > 0)
 				FullSmoothPass_InPlace();
+
+            if (target != null)
+                FullProjectionPass();
 		}
 
 
@@ -240,10 +248,22 @@ void FullSmoothPass_InPlace() {
 				Vector3d vSmoothed = smoothFunc(mesh, vID, SmoothSpeedT);
 				mesh.SetVertex( vID, vSmoothed);
 			}
-
 		}
 
 
 
+        void FullProjectionPass()
+        {
+            foreach ( int vID in mesh.VertexIndices() ) {
+                if (vertex_is_fixed(vID))
+                    continue;
+                Vector3d curpos = mesh.GetVertex(vID);
+                Vector3d projected = target.Project(curpos);
+                mesh.SetVertex(vID, projected);
+            }
+        }
+
+
+
 	}
 }

spatial/DMeshAABBTree.cs

@@ -4,9 +4,10 @@
 
 namespace g3
 {
-    public class DMeshAABBTree3
+    public class DMeshAABBTree3 : ISpatial
     {
         DMesh3 mesh;
+        int mesh_timestamp;
 
         public DMeshAABBTree3(DMesh3 m)
         {
@@ -19,13 +20,17 @@ public DMeshAABBTree3(DMesh3 m)
         public void Build()
         {
             build_by_one_rings();
+            mesh_timestamp = mesh.Timestamp;
         }
 
 
 
-
+        public bool SupportsNearestTriangle { get { return true; } }
         public int FindNearestTriangle(Vector3d p)
         {
+            if (mesh_timestamp != mesh.Timestamp)
+                throw new Exception("DMeshAABBTree3.FindNearestTriangle: mesh has been modified since tree construction");
+
             double fNearestSqr = double.MaxValue;
             int tNearID = -1;
             find_nearest_tri(root_index, p, ref fNearestSqr, ref tNearID);
@@ -97,6 +102,9 @@ public class TreeTraversal
         // walk over tree, calling functions in TreeTraversal object for internal nodes and triangles
         public void DoTraversal(TreeTraversal traversal)
         {
+            if (mesh_timestamp != mesh.Timestamp)
+                throw new Exception("DMeshAABBTree3.DoTraversal: mesh has been modified since tree construction");
+
             tree_traversal(root_index, traversal);
         }
 

spatial/MeshProjectionTarget.cs

@@ -0,0 +1,18 @@
+using System;
+using System.Collections.Generic;
+
+namespace g3
+{
+    public class MeshProjectionTarget : IProjectionTarget
+    {
+        public DMesh3 Mesh { get; set; }
+        public ISpatial Spatial { get; set; }
+
+        public Vector3d Project(Vector3d vPoint, int identifier = -1)
+        {
+            int tNearestID = Spatial.FindNearestTriangle(vPoint);
+            DistPoint3Triangle3 q = MeshQueries.TriangleDistance(Mesh, tNearestID, vPoint);
+            return q.TriangleClosest;
+        }
+    }
+}

spatial/SpatialInterfaces.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+
+namespace g3
+{
+    public interface ISpatial
+    {
+        bool SupportsNearestTriangle { get; }
+        int FindNearestTriangle(Vector3d p);
+    }
+
+
+    public interface IProjectionTarget
+    {
+        Vector3d Project(Vector3d vPoint, int identifier = -1);
+    }
+}