How to modify accurate 3D models to protect technical know-how I have a 3D model from our engineering department with accurate measures of our product (format: VRML) that I want to give to a third party. The third party doesn't need an accurate model for what they are supposed to do with it. Now I want to modify the whole model with little effort to protect our technical know-how. 

Does anybody know a solution in Blender to accomplish that?

I played a little bit with the decimate modifier and it looked promising.
The draw back I see with it, is the disproportionate effort I have to make since I don't know how to apply the modifier on ALL faces of ALL objects in the model.

Is it possible to get a short step-by-step tutorial to get all faces modified at once?

Another question that comes to my mind regarding the protection effect: If I modify the model and export it again to the VRML-format, then the modification I made in Blender is definite/destructive in opposite to the Blender-format itself where it stays non-destructive and I can adjust the modifier again. Am I right?
Setup your decimate modifier on one of the objects.

Then, in object mode, select all objects (A) or all needed object (Shift+RMB).  

Make sure your decimated object is active (different color, usually brighter orange), if it's not, Shift+RMB on it.  

Use Ctrl+L to open the link menu and select "modifiers"


All the selected objects will now have the exact same modifiers as the active object.


About export : modifiers are applied when exporting, so it will be destructive. There can be a checkbox (depending on file format) to apply modifiers or not.