Fixed a long-standing math issue that caused strange jiggling artifac…

…ts for QuadMeshes that were far away from the north pole. Turns out I had messed up the way that the mesh's location relative to the planet was calculated so it wasn't getting translated to the origin correctly when coordinates were converted to mesh space, so we were hitting rounding issues when the X and Y components got large.
SaintGimp · Nov 26, 2010 · b05e527 · b05e527
1 parent 274afad
commit b05e527
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Showing 2 changed files with 3 additions and 2 deletions.
diff --git a/GenesisEngine/Domain/QuadMesh.cs b/GenesisEngine/Domain/QuadMesh.cs
@@ -58,7 +58,8 @@ public void Initialize(double planetRadius, DoubleVector3 planeNormalVector, Dou
             _extents = extents;
             _level = level;
 
-            _locationRelativeToPlanet = (_planeNormalVector) + (_uVector * ((_extents.West + (_extents.Width / 2.0)))) + (_vVector * ((_extents.North + (_extents.Width / 2.0))));
+            // TODO: get this from the QuadNode instead
+            _locationRelativeToPlanet = (_planeNormalVector) + (_uVector * (_extents.North + (_extents.Width / 2.0))) + (_vVector * (_extents.West + (_extents.Width / 2.0)));
             _locationRelativeToPlanet = _locationRelativeToPlanet.ProjectUnitPlaneToUnitSphere() * _planetRadius;
 
             _meshStride = _extents.Width / (_gridSize - 1);

diff --git a/GenesisEngine/Domain/QuadNode.cs b/GenesisEngine/Domain/QuadNode.cs
@@ -53,7 +53,7 @@ public void Initialize(double planetRadius, DoubleVector3 planeNormalVector, Dou
             _extents = extents;
             Level = level;
 
-            _locationRelativeToPlanet = (_planeNormalVector) + (_uVector * ((_extents.West + (_extents.Width / 2.0)))) + (_vVector * ((_extents.North + (_extents.Width / 2.0))));
+            _locationRelativeToPlanet = (_planeNormalVector) + (_uVector * (_extents.North + (_extents.Width / 2.0))) + (_vVector * (_extents.West + (_extents.Width / 2.0)));
             _locationRelativeToPlanet = _locationRelativeToPlanet.ProjectUnitPlaneToUnitSphere() * _planetRadius;
 
             _mesh.Initialize(planetRadius, planeNormalVector, uVector, vVector, extents, level);