From 07b1e8422f1a664ee06fa2383753a6bd3dedd917 Mon Sep 17 00:00:00 2001
From: Christophe Geuzaine <cgeuzaine@ulg.ac.be>
Date: Sun, 3 Jul 2005 07:55:32 +0000
Subject: [PATCH] fix display of normals for very "thin" surfaces with curved
boundaries: this new algorithm should be better
---
Graphics/Geom.cpp | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/Graphics/Geom.cpp b/Graphics/Geom.cpp
index 1bdd2f21e9..278b8df514 100644
--- a/Graphics/Geom.cpp
+++ b/Graphics/Geom.cpp
@@ -1,4 +1,4 @@
-// $Id: Geom.cpp,v 1.87 2005-06-30 07:13:38 remacle Exp $
+// $Id: Geom.cpp,v 1.88 2005-07-03 07:55:32 geuzaine Exp $
//
// Copyright (C) 1997-2005 C. Geuzaine, J.-F. Remacle
//
@@ -304,11 +304,17 @@ void getPlaneSurfaceNormal(Surface *s, double x, double y, double z, double n[3]
t1[0] = x - c->beg->Pos.X;
t1[1] = y - c->beg->Pos.Y;
t1[2] = z - c->beg->Pos.Z;
- for(int i = 1; i < List_Nbr(s->Generatrices); i++){
+ // 1) try to get a point close to 'beg' on the same curve
+ // 2) if we are really unlucky and these two points are aligned
+ // with (x,y,z), which we know is inside or on the boundary of
+ // the surface, then get a point from the next generatrice
+ // 3) repeat
+ for(int i = 0; i < List_Nbr(s->Generatrices); i++){
List_Read(s->Generatrices, i, &c);
- t2[0] = x - c->beg->Pos.X;
- t2[1] = y - c->beg->Pos.Y;
- t2[2] = z - c->beg->Pos.Z;
+ Vertex v = InterpolateCurve(c, 0.1, 0);
+ t2[0] = x - v.Pos.X;
+ t2[1] = y - v.Pos.Y;
+ t2[2] = z - v.Pos.Z;
prodve(t1, t2, n);
if(norme(n))
break;
--
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