From b871ae5cf7b69ca69eab024ce0ae006f0bb6f0ba Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Wed, 5 Jul 2006 13:18:00 +0000
Subject: [PATCH] Added vertex program hack to get round apparent NVidia bug
 when handling vertex texture read.

---
 examples/osgshaderterrain/osgshaderterrain.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/examples/osgshaderterrain/osgshaderterrain.cpp b/examples/osgshaderterrain/osgshaderterrain.cpp
index 8c215ffa6..482b23447 100644
--- a/examples/osgshaderterrain/osgshaderterrain.cpp
+++ b/examples/osgshaderterrain/osgshaderterrain.cpp
@@ -579,7 +579,8 @@ osg::Node* ForestTechniqueManager::createScene(unsigned int /*numTreesToCreates*
                "    vec4 position;\n"
                "    position.x = gl_Vertex.x;\n"
                "    position.y = gl_Vertex.y;\n"
-               "    position.z = texture2D(terrainTexture, texcoord).r;\n"
+               "    float zscale = 0.99;\n"
+               "    position.z = texture2D(terrainTexture, texcoord).r * zscale;\n"
                " \n"
                "    gl_Position     = gl_ModelViewProjectionMatrix * position;\n"
                 "   gl_FrontColor = vec4(1.0,1.0,1.0,1.0);\n"