diff --git a/r_edge.c b/r_edge.c
index e20d3908..eec6f19f 100644
--- a/r_edge.c
+++ b/r_edge.c
@@ -985,6 +985,7 @@ qboolean alphaspans;
 
 
 void D_AlphaSpans16 (espan_t *pspan);
+void D_AddSpans16 (espan_t *pspan);
 void D_BlendSpans16 (espan_t *pspan, int alpha );
 void TurbulentZ8 (espan_t *pspan, int alpha );
 /*
@@ -1072,6 +1073,8 @@ void D_AlphaSurf (surf_t *s)
 
 		if( RI.currententity->curstate.rendermode == kRenderTransAlpha )
 			D_AlphaSpans16(s->spans);
+		else if( RI.currententity->curstate.rendermode == kRenderTransAdd )
+			D_AddSpans16(s->spans);
 		else
 			D_BlendSpans16(s->spans, RI.currententity->curstate.renderamt * 7 / 255 );
 	}
diff --git a/r_scan.c b/r_scan.c
index 8a31b90e..77d151ed 100644
--- a/r_scan.c
+++ b/r_scan.c
@@ -1134,6 +1134,200 @@ void D_BlendSpans16 (espan_t *pspan, int alpha)
 	} while ((pspan = pspan->pnext) != NULL);
 }
 
+
+
+/*
+=============
+D_DrawSpans16
+
+  FIXME: actually make this subdivide by 16 instead of 8!!!
+=============
+*/
+void D_AddSpans16 (espan_t *pspan)
+{
+	int				count, spancount;
+	pixel_t	*pbase, *pdest;
+	fixed16_t		s, t, snext, tnext, sstep, tstep;
+	float			sdivz, tdivz, zi, z, du, dv, spancountminus1;
+	float			sdivz8stepu, tdivz8stepu, zi8stepu;
+	int izi, izistep;
+	short *pz;
+
+	sstep = 0;	// keep compiler happy
+	tstep = 0;	// ditto
+
+	pbase = (unsigned char *)cacheblock;
+
+	sdivz8stepu = d_sdivzstepu * 8;
+	tdivz8stepu = d_tdivzstepu * 8;
+	zi8stepu = d_zistepu * 8;
+	izistep = (int)(d_zistepu * 0x8000 * 0x10000);
+
+	do
+	{
+		pdest = (d_viewbuffer +
+				(r_screenwidth * pspan->v) + pspan->u);
+		pz = d_pzbuffer + (d_zwidth * pspan->v) + pspan->u;
+
+		count = pspan->count;
+
+	// calculate the initial s/z, t/z, 1/z, s, and t and clamp
+		du = (float)pspan->u;
+		dv = (float)pspan->v;
+
+		sdivz = d_sdivzorigin + dv*d_sdivzstepv + du*d_sdivzstepu;
+		tdivz = d_tdivzorigin + dv*d_tdivzstepv + du*d_tdivzstepu;
+		zi = d_ziorigin + dv*d_zistepv + du*d_zistepu;
+		izi = (int)(zi * 0x8000 * 0x10000);
+		z = (float)0x10000 / zi;	// prescale to 16.16 fixed-point
+
+		s = (int)(sdivz * z) + sadjust;
+		if (s > bbextents)
+			s = bbextents;
+		else if (s < 0)
+			s = 0;
+
+		t = (int)(tdivz * z) + tadjust;
+		if (t > bbextentt)
+			t = bbextentt;
+		else if (t < 0)
+			t = 0;
+
+		do
+		{
+		// calculate s and t at the far end of the span
+			if (count >= 8)
+				spancount = 8;
+			else
+				spancount = count;
+
+			count -= spancount;
+
+			if (count)
+			{
+			// calculate s/z, t/z, zi->fixed s and t at far end of span,
+			// calculate s and t steps across span by shifting
+				sdivz += sdivz8stepu;
+				tdivz += tdivz8stepu;
+				zi += zi8stepu;
+				z = (float)0x10000 / zi;	// prescale to 16.16 fixed-point
+
+				snext = (int)(sdivz * z) + sadjust;
+				if (snext > bbextents)
+					snext = bbextents;
+				else if (snext < 8)
+					snext = 8;	// prevent round-off error on <0 steps from
+								//  from causing overstepping & running off the
+								//  edge of the texture
+
+				tnext = (int)(tdivz * z) + tadjust;
+				if (tnext > bbextentt)
+					tnext = bbextentt;
+				else if (tnext < 8)
+					tnext = 8;	// guard against round-off error on <0 steps
+
+				sstep = (snext - s) >> 3;
+				tstep = (tnext - t) >> 3;
+			}
+			else
+			{
+			  // calculate s/z, t/z, zi->fixed s and t at last pixel in span (so
+			  // can't step off polygon), clamp, calculate s and t steps across
+			  // span by division, biasing steps low so we don't run off the
+			  // texture
+				spancountminus1 = (float)(spancount - 1);
+				sdivz += d_sdivzstepu * spancountminus1;
+				tdivz += d_tdivzstepu * spancountminus1;
+				zi += d_zistepu * spancountminus1;
+				z = (float)0x10000 / zi;	// prescale to 16.16 fixed-point
+				snext = (int)(sdivz * z) + sadjust;
+				if (snext > bbextents)
+					snext = bbextents;
+				else if (snext < 8)
+					snext = 8;	// prevent round-off error on <0 steps from
+								//  from causing overstepping & running off the
+								//  edge of the texture
+
+				tnext = (int)(tdivz * z) + tadjust;
+				if (tnext > bbextentt)
+					tnext = bbextentt;
+				else if (tnext < 8)
+					tnext = 8;	// guard against round-off error on <0 steps
+
+				if (spancount > 1)
+				{
+					sstep = (snext - s) / (spancount - 1);
+					tstep = (tnext - t) / (spancount - 1);
+				}
+			  }
+
+
+			// Drawing phrase
+				if (sw_texfilt->value == 0.0f)
+				{
+					do
+					{
+						if (*pz <= (izi >> 16))
+						{
+							pixel_t btemp;
+
+							btemp = *(pbase + (s >> 16) + (t >> 16) * cachewidth);
+
+							btemp = BLEND_ADD( btemp, *pdest);
+							*pdest = btemp;
+							//*pz    = izi >> 16;
+						}
+						pdest++;
+						pz++;
+						izi += izistep;
+						s += sstep;
+						t += tstep;
+					} while (--spancount > 0);
+				}
+				else if (sw_texfilt->value == 1.0f)
+				{
+					do
+					{
+						int idiths = s;
+						int iditht = t;
+
+						int X = (pspan->u + spancount) & 1;
+						int Y = (pspan->v)&1;
+						if (*pz <= (izi >> 16))
+						{
+							pixel_t btemp;
+
+							//Using the kernel
+							idiths += kernel[X][Y][0];
+							iditht += kernel[X][Y][1];
+
+							idiths = idiths >> 16;
+							idiths = idiths ? idiths -1 : idiths;
+
+
+							iditht = iditht >> 16;
+							iditht = iditht ? iditht -1 : iditht;
+
+							btemp = *(pbase + idiths + iditht * cachewidth);
+
+							btemp = BLEND_ADD( btemp, *pdest);
+							*pdest = btemp;
+							//*pz    = izi >> 16;
+						}
+						pdest++;
+						pz++;
+						izi += izistep;
+						s += sstep;
+						t += tstep;
+					} while (--spancount > 0);
+				}
+
+
+		} while (count > 0);
+
+	} while ((pspan = pspan->pnext) != NULL);
+}
+
 #endif
 
 
diff --git a/r_studio.c b/r_studio.c
index 64b653ea..584acbe2 100644
--- a/r_studio.c
+++ b/r_studio.c
@@ -2786,6 +2786,7 @@ set rendermode for studiomodel
 */
 void GL_StudioSetRenderMode( int rendermode )
 {
+	GL_SetRenderMode( rendermode );
 #if 0
 	switch( rendermode )
 	{