+cvar_t r_vis_trace = {0, "r_vis_trace", "0", "test if each portal or leaf is visible using tracelines"};
+cvar_t r_vis_trace_samples = {0, "r_vis_trace_samples", "1", "use this many randomly positioned tracelines each frame to refresh the visible timer"};
+cvar_t r_vis_trace_delay = {0, "r_vis_trace_delay", "1", "keep a portal visible for this many seconds"};
+cvar_t r_vis_trace_eyejitter = {0, "r_vis_trace_eyejitter", "8", "use a random offset of this much on the start of each traceline"};
+cvar_t r_vis_trace_enlarge = {0, "r_vis_trace_enlarge", "0", "make portal bounds bigger for tests by (1+this)*size"};
+cvar_t r_vis_trace_expand = {0, "r_vis_trace_expand", "0", "make portal bounds bigger for tests by this many units"};
+cvar_t r_vis_trace_pad = {0, "r_vis_trace_pad", "8", "accept traces that hit within this many units of the portal"};
+cvar_t r_vis_trace_surfaces = {0, "r_vis_trace_surfaces", "0", "also use tracelines to cull surfaces"};