Thank you jorrit!
I could use blender and python to make a blender object from an image of the sketch using image.getpixelf(x,y) a threshold and Mesh.Primitives.Plane
similar to http://welcometochrisworld.com/2008/06/18/pixel-squaring/
then join the planes to one mesh. Maybe extrude.
Then I could use blender2crystal to create a crystalspace entity? mesh?
Or could I even use blender to place more objects in the scene (setting the entity parameter) and export them along with the floorplan creating a world for cs?
So many more things to aks...
Is there a page that explains how blender, blender2crystal, crystalblend play together and whats the difference between b2c and cb? Or does cb use b2c?
Unfortunately some pages that seem to have explained something a point to the main crystalspace website like http://www.crystalspace3d.org/?page=Creating+art+for+Crystal+Space