From cb3253b57ccf2e9446675a1238fdac46c30eb6a0 Mon Sep 17 00:00:00 2001
From: Richard Brice <37087370+RickBrice@users.noreply.github.com>
Date: Fri, 1 May 2026 14:13:00 -0700
Subject: [PATCH] Removes unnecessary operations when combining horizontal and
 vertical placement matrices for alignment

---
 src/ifcgeom/function_item_evaluator.cpp | 14 --------------
 1 file changed, 14 deletions(-)

diff --git a/src/ifcgeom/function_item_evaluator.cpp b/src/ifcgeom/function_item_evaluator.cpp
index 9bacf94ac0..9458a04fea 100644
--- a/src/ifcgeom/function_item_evaluator.cpp
+++ b/src/ifcgeom/function_item_evaluator.cpp
@@ -104,14 +104,6 @@ struct gradient_fn_evaluator : public fn_evaluator {
         auto xy = horizontal_evaluator_.evaluate(u);
         auto uz = vertical_evaluator_.evaluate(u);
 
-        // curvature is stored in row 3 - capture it and remove it from the xy and uz matrices
-        // so the matrix operations (ie multiplication) works correct.y
-        auto horizontal_curvature = xy.row(3);
-        xy.row(3) = Eigen::Vector4d(0, 0, 0, 1);
-
-        auto vertical_curvature = uz.row(3);
-        uz.row(3) = Eigen::Vector4d(0, 0, 0, 1);
-
         uz(0, 3) = 0.0;      // x is distance along. zero it out so it doesn't add to the x from horizontal
         uz.col(1).swap(uz.col(2)); // uz is 2D in distance along - y plane, swap y and z so elevations become z
         uz.row(1).swap(uz.row(2));
@@ -119,12 +111,6 @@ struct gradient_fn_evaluator : public fn_evaluator {
         Eigen::Matrix4d m;
         m = xy * uz; // combine horizontal and vertical
 
-        // Put curvature back into the solution matrix
-        // curvature for vertical is in column 0, need it to be in column 1
-        // so it doesn't add to curvature for horizontal
-        std::swap(vertical_curvature(0), vertical_curvature(1));
-        m.row(3) = horizontal_curvature + vertical_curvature;
-
         return m;
     }