k3d/share/shaders/k3d_volcube.sl:14:   ShowActiveVol       - if 1 show the active volume instead of density.
k3d/share/shaders/k3d_volcube.sl:196:	     float  ShowActiveVol  = 0;
k3d/share/shaders/k3d_volcube.sl:234:	if(ShowActiveVol == 1)
