From 73043162309ec9821f90335134387272c9197ca4 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sun, 22 Mar 2026 14:12:58 +0000
Subject: [PATCH 1/2] Initial plan


From d100e8db44bc4ce993ee19c722574b58ca3b9ab8 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sun, 22 Mar 2026 14:15:30 +0000
Subject: [PATCH 2/2] Fix SPTerrainLighting to sample SpecularMap like
 MultiPass shader

Co-authored-by: riccardobl <4943530+riccardobl@users.noreply.github.com>
Agent-Logs-Url: https://github.com/jMonkeyEngine/jmonkeyengine/sessions/a30c94c1-aa2a-41dd-b8cd-4059e44d7611
---
 .../MatDefs/Terrain/SPTerrainLighting.frag    | 21 +++++++++++++++++--
 .../MatDefs/Terrain/TerrainLighting.j3md      |  1 +
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/jme3-terrain/src/main/resources/Common/MatDefs/Terrain/SPTerrainLighting.frag b/jme3-terrain/src/main/resources/Common/MatDefs/Terrain/SPTerrainLighting.frag
index 426b665e94..6f7034baff 100644
--- a/jme3-terrain/src/main/resources/Common/MatDefs/Terrain/SPTerrainLighting.frag
+++ b/jme3-terrain/src/main/resources/Common/MatDefs/Terrain/SPTerrainLighting.frag
@@ -3,6 +3,9 @@
 #import "Common/ShaderLib/Lighting.glsllib"
 
 uniform float m_Shininess;
+#ifdef SPECULARMAP
+  uniform sampler2D m_SpecularMap;
+#endif
 
 varying vec4 AmbientSum;
 varying vec4 DiffuseSum;
@@ -615,6 +618,20 @@ void main(){
     #endif
 
 
+    //-----------------------
+    // read shininess or specularColor from specularMap
+    //-----------------------
+    vec4 specularColor = vec4(1.0);
+    float finalShininessValue = m_Shininess;
+    #ifdef SPECULARMAP
+      vec4 specularMapColor = texture2D(m_SpecularMap, texCoord);
+      #ifdef USE_SPECULARMAP_AS_SHININESS
+        finalShininessValue = specularMapColor.r; //assumes that specularMap is a gray-scale reflectivity/shininess map
+      #else
+        specularColor = specularMapColor;
+      #endif
+    #endif
+
     //-----------------------
     // lighting calculations
     //-----------------------
@@ -646,9 +663,9 @@ void main(){
             vec3 viewDir = normalize(-vPos.xyz);
         #endif
 
-        vec2 light = computeLighting(normal, viewDir, lightDir.xyz, lightDir.w  * spotFallOff, m_Shininess);       
+        vec2 light = computeLighting(normal, viewDir, lightDir.xyz, lightDir.w  * spotFallOff, finalShininessValue);       
         gl_FragColor.rgb += DiffuseSum.rgb * lightColor.rgb * diffuseColor.rgb  * vec3(light.x) +
-                            SpecularSum.rgb * vec3(light.y);
+                            SpecularSum.rgb * specularColor.rgb * vec3(light.y);
     }
 
 }
diff --git a/jme3-terrain/src/main/resources/Common/MatDefs/Terrain/TerrainLighting.j3md b/jme3-terrain/src/main/resources/Common/MatDefs/Terrain/TerrainLighting.j3md
index 4eb9c8d7a2..1fa6ce69f6 100644
--- a/jme3-terrain/src/main/resources/Common/MatDefs/Terrain/TerrainLighting.j3md
+++ b/jme3-terrain/src/main/resources/Common/MatDefs/Terrain/TerrainLighting.j3md
@@ -238,6 +238,7 @@ MaterialDef Terrain Lighting {
             DIFFUSEMAP_11_SCALE : DiffuseMap_11_scale
             
             USE_ALPHA : useDiffuseAlpha
+            USE_SPECULARMAP_AS_SHININESS : useSpecularMapAsShininess
         }
     }