From d82c85913a402d402367b616b941084c17b380f5 Mon Sep 17 00:00:00 2001
From: AnyOldName3 <krizdjali+github@gmail.com>
Date: Thu, 24 Jan 2019 23:07:38 +0000
Subject: [PATCH] Don't bother multiplying a matrix by its inverse and applying
 that to the light direction.

Hopefully this will improve numerical stability and reduce shadow flicker a little.
---
 components/sceneutil/mwshadowtechnique.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/components/sceneutil/mwshadowtechnique.cpp b/components/sceneutil/mwshadowtechnique.cpp
index 6f3d34cb1a..08117b4f95 100644
--- a/components/sceneutil/mwshadowtechnique.cpp
+++ b/components/sceneutil/mwshadowtechnique.cpp
@@ -474,7 +474,7 @@ void MWShadowTechnique::LightData::setLightData(osg::RefMatrix* lm, const osg::L
         lightDir.set(-lightPos.x(), -lightPos.y(), -lightPos.z());
         lightDir.normalize();
         OSG_INFO<<"   Directional light, lightPos="<<lightPos<<", lightDir="<<lightDir<<std::endl;
-        if (lightMatrix.valid())
+        if (lightMatrix.valid() && *lightMatrix != osg::Matrixf(modelViewMatrix))
         {
             OSG_INFO<<"   Light matrix "<<*lightMatrix<<std::endl;
             osg::Matrix lightToLocalMatrix(*lightMatrix * osg::Matrix::inverse(modelViewMatrix) );