diff --git a/src/gl/dynlights/gl_lightbuffer.cpp b/src/gl/dynlights/gl_lightbuffer.cpp
index 1f105b4ea6..979cbff775 100644
--- a/src/gl/dynlights/gl_lightbuffer.cpp
+++ b/src/gl/dynlights/gl_lightbuffer.cpp
@@ -173,13 +173,6 @@ int FLightBuffer::UploadLights(FDynLightData &data)
 	if (mBufferPointer == NULL) return -1;
 	copyptr = mBufferPointer + mIndex * 4;
 
-	static unsigned int lastindex = 0;
-	if (mIndex > lastindex)
-	{
-		Printf("Light index: %d, size: %d\n", mIndex, totalsize);
-		lastindex = mIndex;
-	}
-
 	float parmcnt[] = { 0, float(size0), float(size0 + size1), float(size0 + size1 + size2) };
 
 	memcpy(&copyptr[0], parmcnt, 4 * sizeof(float));
diff --git a/src/gl/scene/gl_flats.cpp b/src/gl/scene/gl_flats.cpp
index ac185aee98..378cd81f0e 100644
--- a/src/gl/scene/gl_flats.cpp
+++ b/src/gl/scene/gl_flats.cpp
@@ -639,6 +639,7 @@ void GLFlat::ProcessSector(sector_t * frontsector)
 			if ((rover->flags&(FF_EXISTS|FF_RENDERPLANES|FF_THISINSIDE))==(FF_EXISTS|FF_RENDERPLANES))
 			{
 				if (rover->flags&FF_FOG && gl_fixedcolormap) continue;
+				if (rover->top.copied) continue;	// this plane has been dynamically created and does not produce any rendered surface.
 				if (rover->flags&(FF_INVERTPLANES|FF_BOTHPLANES))
 				{
 					fixed_t ff_top=rover->top.plane->ZatPoint(CenterSpot(sector));
@@ -679,6 +680,7 @@ void GLFlat::ProcessSector(sector_t * frontsector)
 			if ((rover->flags&(FF_EXISTS|FF_RENDERPLANES|FF_THISINSIDE))==(FF_EXISTS|FF_RENDERPLANES))
 			{
 				if (rover->flags&FF_FOG && gl_fixedcolormap) continue;
+				if (rover->bottom.copied) continue;	// this plane has been dynamically created and does not produce any rendered surface.
 				if (rover->flags&(FF_INVERTPLANES|FF_BOTHPLANES))
 				{
 					fixed_t ff_bottom=rover->bottom.plane->ZatPoint(CenterSpot(sector));