[Therion] Plan only walls and centerline

[Boldt, Markus]

 Hi, 
I`am sure it is possible with Therion to get a plan without any
speleothemes. The plan is ready drawn, but I need a plan only with walls
and pillars and the centerline but without any other drawings. I have
searched in the Wiki but without success. Please give me some help. I
cannot believe, that I must delete all previously drawn things in the
*.th2-File. 
regards 
Markus