Index: exp_fmt_amf.c
===================================================================
--- exp_fmt_amf.c	(revision 35971)
+++ exp_fmt_amf.c	(revision 35972)
@@ -73,6 +73,11 @@
 	verthash_add_triangle(&verthash, vert[0], vert[1], vert[2]);
 }
 
+static void amf_new_obj(float r, float g, float b)
+{
+	verthash_new_obj(&verthash, r, g, b);
+}
+
 static void amf_print_header(FILE *f)
 {
 	fprintf(f, "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n");
@@ -94,13 +99,31 @@
 		rnd_fprintf(f, "    <vertex><coordinates> <x>%.09mm</x>\t<y>%.09mm</y>\t<z>%.09mm</z> </coordinates></vertex>\n", c[0], c[1], c[2]);
 	fprintf(f, "   </vertices>\n");
 
-	fprintf(f, "   <volume>\n");
-	for(n = 0, vx = verthash.triangles.array; n < verthash.triangles.used; n += 3, vx += 3)
+	for(n = 0, vx = verthash.triangles.array; n < verthash.triangles.used; n += 3, vx += 3) {
+		if (vx[0] < 0) {
+			if (n != 0)
+				fprintf(f, "   </volume>\n");
+			fprintf(f, "   <volume materialid=\"%ld\">\n", (long)-vx[0]);
+			vx++;
+			n++;
+			continue; /* shift colors */
+		}
 		rnd_fprintf(f, "    <triangle> <v1>%ld</v1>\t<v2>%ld</v2>\t<v3>%ld</v3> </triangle>\n", vx[0], vx[1], vx[2]);
+	}
 	fprintf(f, "   </volume>\n");
-
 	fprintf(f, "  </mesh>\n");
 	fprintf(f, " </object>\n");
+
+	for(n = 0, vx = verthash.triangles.array; n < verthash.triangles.used; n += 3, vx += 3) {
+		if (vx[0] < 0) {
+			fprintf(f, "  <material id=\"%ld\">\n", (long)-vx[0]);
+			vx++;
+			n++;
+			fprintf(f, "    <color><r>%.6f</r><g>%.6f</g><b>%.6f</b></color>\n", (double)vx[0]/1000000, (double)vx[1]/1000000, (double)vx[2]/1000000);
+			fprintf(f, "  </material>\n");
+		}
+	}
+
 	fprintf(f, "</amf>\n");
 
 	verthash_uninit(&verthash);
Index: exp_fmt_stl.c
===================================================================
--- exp_fmt_stl.c	(revision 35971)
+++ exp_fmt_stl.c	(revision 35972)
@@ -88,6 +88,10 @@
 	fprintf(f, " endfacet\n");
 }
 
+static void stl_new_obj(float r, float g, float b)
+{
+}
+
 static void stl_print_header(FILE *f)
 {
 	fprintf(f, "solid pcb\n");
Index: export_stl.c
===================================================================
--- export_stl.c	(revision 35971)
+++ export_stl.c	(revision 35972)
@@ -422,10 +422,14 @@
 
 	fp2t_triangulate(&tri);
 
-	if (fmt_amf)
+	if (fmt_amf) {
 		amf_print_header(f);
-	else
+		amf_new_obj(0, 0.3, 0);
+	}
+	else {
 		stl_print_header(f);
+		stl_new_obj(0, 0.3, 0);
+	}
 
 	/* write the top and bottom plane */
 	for(n = 0; n < tri.TriangleCount; n++) {
Index: stl_models.c
===================================================================
--- stl_models.c	(revision 35971)
+++ stl_models.c	(revision 35972)
@@ -211,6 +211,7 @@
 	htsp_t models;
 	const char *mod;
 	htsp_entry_t *e;
+	int first = 1;
 
 	htsp_init(&models, strhash, strkeyeq);
 
@@ -236,6 +237,14 @@
 			if (srot == NULL)
 				srot = pcb_attribute_get(&subc->Attributes, "stl-rotate");
 
+			if (first) {
+				if (fmt_amf)
+					amf_new_obj(0, 0, 0);
+				else
+					stl_new_obj(0, 0, 0);
+				first = 0;
+			}
+
 			stl_model_place(&pcb->hidlib, outf, &models, mod, ox, oy, rot, on_bottom, sxlate, srot, maxy, z0, z1, fmt_amf);
 		}
 	} PCB_END_LOOP;
Index: verthash.c
===================================================================
--- verthash.c	(revision 35971)
+++ verthash.c	(revision 35972)
@@ -18,6 +18,7 @@
 	vtc0_t vxcoords;
 	vtl0_t triangles;
 	long next_id;
+	long next_obj;
 } verthash_t;
 
 
@@ -37,6 +38,7 @@
 	vtc0_init(&vh->vxcoords);
 	vtl0_init(&vh->triangles);
 	vh->next_id = 0;
+	vh->next_obj = 2;
 }
 
 static void verthash_uninit(verthash_t *vh)
@@ -81,3 +83,13 @@
 	v3 = verthash_add_vertex(vh, x3, y3, z3);
 	verthash_add_triangle(vh, v1, v2, v3);
 }
+
+static void verthash_new_obj(verthash_t *vh, float r, float g, float b)
+{
+	vtl0_append(&vh->triangles, -vh->next_obj);
+	vh->next_obj++;
+
+	vtl0_append(&vh->triangles, rnd_round(r*1000000));
+	vtl0_append(&vh->triangles, rnd_round(g*1000000));
+	vtl0_append(&vh->triangles, rnd_round(b*1000000));
+}