diff --git a/Aquaria/WaterSurfaceRender.cpp b/Aquaria/WaterSurfaceRender.cpp
index 60e864b..8516dfb 100644
--- a/Aquaria/WaterSurfaceRender.cpp
+++ b/Aquaria/WaterSurfaceRender.cpp
@@ -98,7 +98,7 @@ void WaterSurfaceRender::prepareRender()
 		if (dsq->useFrameBuffer && dsq->frameBuffer.isInited())
 		{
 			qSurface->alphaMod = 0.5f;
-			fbEffectVisible = this->isOnScreen();
+			fbEffectVisible = this->isRectPartiallyOnScreen();
 		}
 	}
 	else
@@ -197,7 +197,7 @@ void WaterSurfaceRender::render(const RenderState& rs) const
 
 void WaterSurfaceRender::onRender(const RenderState& rs) const
 {
-	if (!fbEffectVisible || game->waterLevel == 0) return;
+	if (!fbEffectVisible || game->waterLevel.x == 0) return;
 
 
 	core->frameBuffer.bindTexture(core->frameBuffer.getCurrentPage() - 1);
diff --git a/BBGE/Core.cpp b/BBGE/Core.cpp
index d4e6395..1155d79 100644
--- a/BBGE/Core.cpp
+++ b/BBGE/Core.cpp
@@ -645,6 +645,32 @@ Vector Core::getWindowPosition(const Vector &worldpos) const
 	return (worldpos - cameraPos) * globalScale.x;
 }
 
+bool Core::isRectInWindowCoordsPartiallyOnScreen(const Vector& center, const Vector& wh) const
+{
+	const float xo = getVirtualOffX();
+	const float yo = getVirtualOffY();
+	const Vector topleft(-xo, -yo);
+	const Vector bottomright(800 + xo, 600 + yo);
+	const Vector half = wh * 0.5f;
+	const Vector a = topleft - half;
+	const Vector b = bottomright + half;
+	return center.x >= a.x && center.x <= b.x
+		&& center.y >= a.y && center.y <= b.y;
+}
+
+bool Core::isRectInWindowCoordsFullyOnScreen(const Vector& center, const Vector& wh) const
+{
+	const float xo = getVirtualOffX();
+	const float yo = getVirtualOffY();
+	const Vector topleft(-xo, -yo);
+	const Vector bottomright(800 + xo, 600 + yo);
+	const Vector half = wh * 0.5f;
+	const Vector a = topleft + half;
+	const Vector b = bottomright - half;
+	return center.x >= a.x && center.x <= b.x
+		&& center.y >= a.y && center.y <= b.y;
+}
+
 bool Core::getMouseButtonState(int m)
 {
 	int mcode=m;
diff --git a/BBGE/Core.h b/BBGE/Core.h
index 173b014..a66a74e 100644
--- a/BBGE/Core.h
+++ b/BBGE/Core.h
@@ -279,6 +279,9 @@ public:
 	Vector getGamePosition(const Vector &winpos) const;
 	Vector getWindowPosition(const Vector& worldpos) const;
 
+	bool isRectInWindowCoordsPartiallyOnScreen(const Vector& center, const Vector& wh) const;
+	bool isRectInWindowCoordsFullyOnScreen(const Vector& center, const Vector& wh) const;
+
 
 	Vector screenCenter;
 
diff --git a/BBGE/RenderObject.cpp b/BBGE/RenderObject.cpp
index 53edeab..112d3ac 100644
--- a/BBGE/RenderObject.cpp
+++ b/BBGE/RenderObject.cpp
@@ -35,6 +35,13 @@ bool	RenderObject::renderCollisionShape			= false;
 size_t	RenderObject::lastTextureApplied			= 0;
 bool	RenderObject::renderPaths					= false;
 
+
+MotionBlurData::MotionBlurData()
+	: transition(false), frameOffsetCounter(0), frameOffset(0), transitionTimer(0)
+{
+}
+
+
 void RenderObject::toggleAlpha(float t)
 {
 	if (alpha.x < 0.5f)
@@ -897,7 +904,52 @@ bool RenderObject::isCoordinateInRadius(const Vector &pos, float r) const
 	return (d.getSquaredLength2D() < r*r);
 }
 
-MotionBlurData::MotionBlurData()
-	: transition(false), frameOffsetCounter(0), frameOffset(0), transitionTimer(0)
+Vector RenderObject::getFollowCameraPosition(const Vector& v) const
+{
+	assert(layer != LR_NONE);
+	assert(!parent); // this makes no sense when we're not a root object
+	if(neverFollowCamera)
+		return v;
+	const RenderObjectLayer &rl = core->renderObjectLayers[layer];
+	Vector M = rl.followCameraMult;
+	float F = followCamera;
+	if(!F)
+		F = rl.followCamera;
+	if (F <= 0)
+		return v;
+
+	/* Originally, not accounting for parallax lock on an axis, this was:
+		pos = v - core->screenCenter;
+		pos *= F;
+		pos = core->screenCenter + pos;
+	*/
+
+	// uppercase are effectively constants that are not per-object
+	// lowercase are per-object
+
+	// more concise math:
+	//const Vector pos = (v - core->screenCenter) * F + core->screenCenter;
+	//return v * (Vector(1,1) - M) + (pos * M); // lerp
+
+	// optimized and rearranged
+	const Vector C = core->screenCenter;
+	const Vector M1 = Vector(1,1) - M;
+	const Vector T = C * (1 - F);
+
+	const Vector pos = T + (F * v);
+	return v * M1 + (pos * M); // lerp, used to select whether to use original v or parallax-corrected v
+}
+
+bool RenderObject::isRectPartiallyOnScreen() const
+{
+	Vector p = core->getWindowPosition(getFollowCameraPosition(position + offset));
+	Vector sz = Vector(width, height) * getRealScale();
+	return core->isRectInWindowCoordsPartiallyOnScreen(p, sz);
+}
+
+bool RenderObject::isRectFullyOnScreen() const
 {
+	Vector p = core->getWindowPosition(getFollowCameraPosition(position + offset));
+	Vector sz = Vector(width, height) * getRealScale();
+	return core->isRectInWindowCoordsFullyOnScreen(p, sz);
 }
diff --git a/BBGE/RenderObject.h b/BBGE/RenderObject.h
index 16f934e..2a730b1 100644
--- a/BBGE/RenderObject.h
+++ b/BBGE/RenderObject.h
@@ -177,6 +177,9 @@ public:
 	// HACK: This is defined in RenderObject_inline.h because it needs
 	// the class Core definition.  --achurch
 	inline bool isOnScreen() const;
+	bool isRectPartiallyOnScreen() const;
+	bool isRectFullyOnScreen() const;
+
 
 	bool isCoordinateInRadius(const Vector &pos, float r) const;
 
@@ -206,7 +209,7 @@ public:
 
 	// Defined in RenderObject_inline.h
 	inline Vector getFollowCameraPosition() const;
-	inline Vector getFollowCameraPosition(const Vector& pos) const;
+	Vector getFollowCameraPosition(const Vector& pos) const;
 
 	void lookAt(const Vector &pos, float t, float minAngle, float maxAngle, float offset=0);
 	inline RenderObject *getParent() const {return parent;}
diff --git a/BBGE/RenderObject_inline.h b/BBGE/RenderObject_inline.h
index 4bcdad2..ebdcc00 100644
--- a/BBGE/RenderObject_inline.h
+++ b/BBGE/RenderObject_inline.h
@@ -37,40 +37,5 @@ Vector RenderObject::getFollowCameraPosition() const
 	return getFollowCameraPosition(position);
 }
 
-Vector RenderObject::getFollowCameraPosition(const Vector& v) const
-{
-	assert(layer != LR_NONE);
-	assert(!parent); // this makes no sense when we're not a root object
-	if(neverFollowCamera)
-		return v;
-	const RenderObjectLayer &rl = core->renderObjectLayers[layer];
-	Vector M = rl.followCameraMult;
-	float F = followCamera;
-	if(!F)
-		F = rl.followCamera;
-	if (F <= 0)
-		return v;
-
-	/* Originally, not accounting for parallax lock on an axis, this was:
-		pos = v - core->screenCenter;
-		pos *= F;
-		pos = core->screenCenter + pos;
-	*/
-
-	// uppercase are effectively constants that are not per-object
-	// lowercase are per-object
-
-	// more concise math:
-	//const Vector pos = (v - core->screenCenter) * F + core->screenCenter;
-	//return v * (Vector(1,1) - M) + (pos * M); // lerp
-
-	// optimized and rearranged
-	const Vector C = core->screenCenter;
-	const Vector M1 = Vector(1,1) - M;
-	const Vector T = C * (1 - F);
-
-	const Vector pos = T + (F * v);
-	return v * M1 + (pos * M); // lerp, used to select whether to use original v or parallax-corrected v
-}
 
 #endif