diff --git a/simgear/scene/model/animation.cxx b/simgear/scene/model/animation.cxx
index 31d0862..e8a241c 100644
--- a/simgear/scene/model/animation.cxx
+++ b/simgear/scene/model/animation.cxx
@@ -105,30 +105,28 @@ set_translation (osg::Matrix &matrix, double position_m, const SGVec3d &axis)
  * Modify property value by step and scroll settings in texture translations
  */
 static double
-apply_mods(double property, double step, double scroll, double bias)
+apply_mods(double property, double step, double scroll, double bias=0)
 {
-
-  double modprop;
-  property += bias;
-  if(step > 0) {
-    double scrollval = 0.0;
-    if(scroll > 0) {
-      // calculate scroll amount (for odometer like movement)
-      double remainder  =  step - fmod(fabs(property), step);
-      if (remainder < scroll) {
-        scrollval = (scroll - remainder) / scroll * step;
-      }
-    }
-  // apply stepping of input value
-  if(property > 0) 
-     modprop = ((floor(property/step) * step) + scrollval);
-  else
-     modprop = ((ceil(property/step) * step) + scrollval);
-  } else {
-     modprop = property;
-  }
-  return modprop;
-
+  property += bias; 
+  if (step <= 0) return property;
+  if (scroll < 0) scroll = step * 1e-6;
+
+  double sign(1.0);
+  if(property < 0) {
+    property = -property;
+    sign = -sign;
+  }
+  double quantized = step * floor(property/step);
+
+  double scrollval(0.0);
+  if(scroll > 0) {
+    // calculate scroll amount (for odometer like movement)
+    double togo = step + quantized - property;
+    if (togo < scroll) {
+      scrollval = step * (scroll - togo) / scroll;
+    } 
+  } 
+  return sign * (quantized + scrollval);
 }
 
 /**
@@ -234,7 +232,7 @@ public:
     _scale(1),
     _offset(0),
     _step(0),
-    _scroll(0),
+    _scroll(-1),
     _bias(0),
     _min(-SGLimitsd::max()),
     _max(SGLimitsd::max())
@@ -2030,7 +2028,7 @@ SGTexTransformAnimation::appendTexTranslate(const SGPropertyNode* config,
     SGTexTableValue* value;
     value = new SGTexTableValue(inputNode, table);
     value->setStep(config->getDoubleValue("step", 0));
-    value->setScroll(config->getDoubleValue("scroll", 0));
+    value->setScroll(config->getDoubleValue("scroll", -1));
     value->setBias(config->getDoubleValue("bias", 0));
     animationValue = value;
   } else {
@@ -2039,7 +2037,7 @@ SGTexTransformAnimation::appendTexTranslate(const SGPropertyNode* config,
     value->setScale(config->getDoubleValue("factor", 1));
     value->setOffset(config->getDoubleValue("offset", 0));
     value->setStep(config->getDoubleValue("step", 0));
-    value->setScroll(config->getDoubleValue("scroll", 0));
+    value->setScroll(config->getDoubleValue("scroll", -1));
     value->setBias(config->getDoubleValue("bias", 0));
     value->setMin(config->getDoubleValue("min", -SGLimitsd::max()));
     value->setMax(config->getDoubleValue("max", SGLimitsd::max()));