From 394ae197fbe082ee32321b60bcae579262fa6df0 Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Tue, 19 Dec 2017 23:24:30 +0100
Subject: [PATCH] fix broken transparency mode of mesh objects

---
 src/Mod/Mesh/Gui/SoFCIndexedFaceSet.cpp | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/Mod/Mesh/Gui/SoFCIndexedFaceSet.cpp b/src/Mod/Mesh/Gui/SoFCIndexedFaceSet.cpp
index b73e99f0da..7ba2a3c796 100644
--- a/src/Mod/Mesh/Gui/SoFCIndexedFaceSet.cpp
+++ b/src/Mod/Mesh/Gui/SoFCIndexedFaceSet.cpp
@@ -76,8 +76,16 @@ void SoFCIndexedFaceSet::GLRender(SoGLRenderAction *action)
     if (this->coordIndex.getNum() < 3)
         return;
 
-    if (!this->shouldGLRender(action))
+    if (!this->shouldGLRender(action)) {
+        // Transparency is handled inside 'shouldGLRender' but the base class
+        // somehow misses to reset the blending mode. This causes SoGLLazyElement
+        // not to switch on and off GL_BLEND mode and thus transparency doesn't
+        // work as expected. Calling SoMaterialBundle::sendFirst seems to fix the
+        // problem.
+        SoMaterialBundle mb(action);
+        mb.sendFirst();
         return;
+    }
 
     SoState * state = action->getState();
     SbBool mode = Gui::SoFCInteractiveElement::get(state);