From c3d7c7de214d757edbc32e073a157ea6e8a4eab4 Mon Sep 17 00:00:00 2001
From: AnyOldName3 <krizdjali+github@gmail.com>
Date: Tue, 23 Jan 2018 20:13:37 +0000
Subject: [PATCH] Prevent first-person meshes disappearing.

---
 apps/openmw/mwrender/npcanimation.cpp | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/apps/openmw/mwrender/npcanimation.cpp b/apps/openmw/mwrender/npcanimation.cpp
index 08e376f083..eca9bb3e65 100644
--- a/apps/openmw/mwrender/npcanimation.cpp
+++ b/apps/openmw/mwrender/npcanimation.cpp
@@ -350,11 +350,16 @@ public:
         if (cv->getProjectionMatrix()->getPerspective(fov, aspect, zNear, zFar))
         {
             fov = mFov;
-            osg::RefMatrix* newProjectionMatrix = new osg::RefMatrix(*cv->getProjectionMatrix());
+            osg::ref_ptr<osg::RefMatrix> newProjectionMatrix = new osg::RefMatrix();
             newProjectionMatrix->makePerspective(fov, aspect, zNear, zFar);
-            cv->pushProjectionMatrix(newProjectionMatrix);
+            osg::ref_ptr<osg::RefMatrix> invertedOldMatrix = cv->getProjectionMatrix();
+            invertedOldMatrix = new osg::RefMatrix(osg::RefMatrix::inverse(*invertedOldMatrix));
+            osg::ref_ptr<osg::RefMatrix> viewMatrix = new osg::RefMatrix(*cv->getModelViewMatrix());
+            viewMatrix->postMult(*newProjectionMatrix);
+            viewMatrix->postMult(*invertedOldMatrix);
+            cv->pushModelViewMatrix(viewMatrix, osg::Transform::ReferenceFrame::ABSOLUTE_RF);
             traverse(node, nv);
-            cv->popProjectionMatrix();
+            cv->popModelViewMatrix();
         }
         else
             traverse(node, nv);