Index: hid_cam.c
===================================================================
--- hid_cam.c	(revision 37319)
+++ hid_cam.c	(revision 37320)
@@ -263,6 +263,8 @@
 				dst->flip_x = 1;
 			else if (strcmp(curr, "flip_y") == 0)
 				dst->flip_y = 1;
+			else if (strcmp(curr, "force_nonempty") == 0)
+				dst->force_nonempty = 1;
 			else
 				rnd_message(RND_MSG_ERROR, "CAM: ignoring unknown global parameter [%s]\n", curr);
 		}
@@ -361,6 +363,13 @@
 	return -1;
 }
 
+rnd_bool pcb_cam_layergrp_is_empty(pcb_cam_t *dst, pcb_board_t *PCB, rnd_layergrp_id_t group)
+{
+	if (dst->force_nonempty)
+		return 0;
+	return pcb_layergrp_is_empty(PCB, group);
+}
+
 int pcb_cam_end(pcb_cam_t *dst)
 {
 	free(dst->inst);