javac.exe did create ConsolePhotoGenerator.java

I have some doubts about this. It should have created ConsolePhotoGenerator.class file. To simplify its use, remove the first line package com.eteks.sweethome3d.utilities; from the source code, and compile it again.

The java command is followed by a class name, not a file, i.e. the basic command must be: But you also need to add to the class path all the libraries required to execute that class! If you host the ConsolePhotoGenerator.class file generated by javac in the subdirectory lib of Sweet Home 3D installation directory, then the command should look like this: if run from the Sweet Home 3D installation directory. Add at the end of this command the path of the sh3d file and the path where the image should be saved.