Added ShadowSettings::s/getMaximumShadowMapDistance(double) property, usage of these property in ViewDependentShadowMap,

and setting of it with --max-shadow-distance <double> in the osgshadow example.

examples/osgshadow/osgshadow.cpp

@@ -742,6 +742,7 @@ int main(int argc, char** argv)
     arguments.getApplicationUsage()->addCommandLineOption("--two-sided", "Use two-sided stencil extension for shadow volumes.");
     arguments.getApplicationUsage()->addCommandLineOption("--two-pass", "Use two-pass stencil for shadow volumes.");
     arguments.getApplicationUsage()->addCommandLineOption("--near-far-mode","COMPUTE_NEAR_USING_PRIMITIVES, COMPUTE_NEAR_FAR_USING_PRIMITIVES, COMPUTE_NEAR_FAR_USING_BOUNDING_VOLUMES, DO_NOT_COMPUTE_NEAR_FAR");
+    arguments.getApplicationUsage()->addCommandLineOption("--max-shadow-distance","<float> Maximum distance that the shadow map should extend from the eye point.");
 
     // construct the viewer.
     osgViewer::Viewer viewer(arguments);
@@ -859,6 +860,14 @@ int main(int argc, char** argv)
         }
         OSG_NOTICE<<std::endl;
     }
+
+    double distance;
+    if (arguments.read("--max-shadow-distance",distance))
+    {
+        settings->setMaximumShadowMapDistance(distance);
+        OSG_NOTICE<<"MaximumShadowMapDistance set to "<<settings->getMaximumShadowMapDistance()<<std::endl;
+    }
+
     
     osg::ref_ptr<osgShadow::MinimalShadowMap> msm = NULL;
     if (arguments.read("--no-shadows"))

include/osgShadow/ShadowSettings

@@ -65,6 +65,10 @@ class OSGSHADOW_EXPORT ShadowSettings : public osg::Object
         void setMinimumShadowMapNearFarRatio(double ratio) { _minimumShadowMapNearFarRatio = ratio; }
         double getMinimumShadowMapNearFarRatio() const { return _minimumShadowMapNearFarRatio; }
 
+        void setMaximumShadowMapDistance(double distance) { _maximumShadowMapDistance = distance; }
+        double getMaximumShadowMapDistance() const { return _maximumShadowMapDistance; }
+        
+
         enum ShadowMapProjectionHint
         {
             ORTHOGRAPHIC_SHADOW_MAP,
@@ -126,6 +130,7 @@ class OSGSHADOW_EXPORT ShadowSettings : public osg::Object
         osg::Vec2s              _textureSize;
 
         double                  _minimumShadowMapNearFarRatio;
+        double                  _maximumShadowMapDistance;
         ShadowMapProjectionHint _shadowMapProjectionHint;
         double                  _perspectiveShadowMapCutOffAngle;
 

src/osgShadow/ShadowSettings.cpp

@@ -12,6 +12,7 @@
 */
 
 #include <osgShadow/ShadowSettings>
+#include <float.h>
 
 using namespace osgShadow;
 
@@ -24,6 +25,7 @@ ShadowSettings::ShadowSettings():
     _useShadowMapTextureOverride(true),
     _textureSize(2048,2048),
     _minimumShadowMapNearFarRatio(0.05),
+    _maximumShadowMapDistance(DBL_MAX),
     _shadowMapProjectionHint(PERSPECTIVE_SHADOW_MAP),
     _perspectiveShadowMapCutOffAngle(2.0),
     _numShadowMapsPerLight(1),
@@ -46,6 +48,7 @@ ShadowSettings::ShadowSettings(const ShadowSettings& ss, const osg::CopyOp& copy
     _useShadowMapTextureOverride(ss._useShadowMapTextureOverride),
     _textureSize(ss._textureSize),
     _minimumShadowMapNearFarRatio(ss._minimumShadowMapNearFarRatio),
+    _maximumShadowMapDistance(ss._maximumShadowMapDistance),
     _shadowMapProjectionHint(ss._shadowMapProjectionHint),
     _perspectiveShadowMapCutOffAngle(ss._perspectiveShadowMapCutOffAngle),
     _numShadowMapsPerLight(ss._numShadowMapsPerLight),

src/osgShadow/ViewDependentShadowMap.cpp

@@ -799,9 +799,12 @@ void ViewDependentShadowMap::cull(osgUtil::CullVisitor& cv)
         cv.computeNearPlane();
     }
 
-    //minZNear = osg::maximum(10.0,minZNear);
+    // clamp the minZNear and maxZFar to those provided by ShadowSettings
-    //maxZFar = osg::minimum(60.0,maxZFar);
+    maxZFar = osg::minimum(settings->getMaximumShadowMapDistance(),maxZFar);
+    if (minZNear>maxZFar) minZNear = maxZFar*settings->getMinimumShadowMapNearFarRatio();
 
+    //OSG_NOTICE<<"maxZFar "<<maxZFar<<std::endl;
+    
     Frustum frustum(&cv, minZNear, maxZFar);
 
     // return compute near far mode back to it's original settings