Concerning the SunFlow and YafaRay rendering engines, their parameters can be modified in a SweetHome3D.l4j.ini file by adding the prefix "[font=courier new]-Dcom.eteks.sweethome3d.j3d.PhotoRenderer.[/font]" or "[font=courier new]-Dcom.eteks.sweethome3d.j3d.YafarayRenderer.[/font]" .