juanjpro wrote:3D World Studio comes with a b3d exporter by itself (you don't need to search for one), you just have to go to 3D World Studio's "File" menu (the one on the top of your window), and select "Export".
After the export window opens, just select "Blitz3D model" from the "Save as type" drop-down menu, select a directory to save the file (the game's graphics directory), and the model will be saved along with the lightmaps and textures.
I recommend using YouTube's search engine to find videos as a guide next time, or maybe Google will be useful enough if you choose to read.
If this hasn't helped you, you might have a different version/application with the same name, where a Blitz3D exporter is not available/isn't found by the same means.
but i can't export, here's proof: