From 8216410e7d50ffd2bf6d0a62810880eb9da83c3b Mon Sep 17 00:00:00 2001
From: cody glassman <glassmancody.info@gmail.com>
Date: Sat, 8 Jan 2022 16:19:42 -0800
Subject: [PATCH] add white ambient to spell VFX as in Morrowind

---
 CHANGELOG.md                       |  1 +
 apps/openmw/mwrender/animation.cpp | 18 +++++++++++++++++-
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 419727c87d..3ee15e0ea3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,7 @@
     Bug #4602: Robert's Bodies: crash inside createInstance()
     Bug #4700: Editor: Incorrect command implementation
     Bug #4744: Invisible particles must still be processed
+    Bug #4949: Incorrect particle lighting
     Bug #5088: Sky abruptly changes direction during certain weather transitions
     Bug #5100: Persuasion doesn't always clamp the resulting disposition
     Bug #5120: Scripted object spawning updates physics system
diff --git a/apps/openmw/mwrender/animation.cpp b/apps/openmw/mwrender/animation.cpp
index bf0ed04055..732ffd33aa 100644
--- a/apps/openmw/mwrender/animation.cpp
+++ b/apps/openmw/mwrender/animation.cpp
@@ -7,6 +7,7 @@
 #include <osg/BlendFunc>
 #include <osg/Material>
 #include <osg/Switch>
+#include <osg/LightModel>
 
 #include <osgParticle/ParticleSystem>
 #include <osgParticle/ParticleProcessor>
@@ -372,6 +373,19 @@ namespace
     private:
         int mEffectId;
     };
+
+    osg::ref_ptr<osg::LightModel> getVFXLightModelInstance()
+    {
+        static osg::ref_ptr<osg::LightModel> lightModel = nullptr;
+
+        if (!lightModel)
+        {
+            lightModel = new osg::LightModel;
+            lightModel->setAmbientIntensity({1,1,1,1});
+        }
+
+        return lightModel;
+    }
 }
 
 namespace MWRender
@@ -1547,7 +1561,9 @@ namespace MWRender
         parentNode->addChild(trans);
 
         osg::ref_ptr<osg::Node> node = mResourceSystem->getSceneManager()->getInstance(model, trans);
-        node->getOrCreateStateSet()->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
+
+        // Morrowind has a white ambient light attached to the root VFX node of the scenegraph
+        node->getOrCreateStateSet()->setAttributeAndModes(getVFXLightModelInstance(), osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE);
 
         SceneUtil::FindMaxControllerLengthVisitor findMaxLengthVisitor;
         node->accept(findMaxLengthVisitor);