http://www.3d-brush.com/
It is free , a sort of Zbrush like but I cannot find how to obtain a NM from it.

Thank you for this link! This will be very useful for creating normal and displacement maps!

The problems is that I can't see how to made NM using this ...I was able only to export a skin like this that is not a NM.



Then I exported a detailed model and it was huge: 1 gigabyte.
Besides those problems, the software looks awesome and I hope that someone can find the way to using it with 3dgs in an efficent way.

isn't that a depthmap? heightmap? dispacement map? however you want to call it. you have to transform it to a normalmap...

yeah, there is a plug in for Photoshop that does it.

and gimp has also a great plugin

I did using crazybump ( see the map below) and then I tryed to apply the shader to a model , but the engine ( I using the NM shader from the shader forum) does not show any bumpness.
Perhaps I need some procedure to convert an heighmap to a NM?

no, it's a tangent space normal map, that's correct as far as i can tell.

Sorry for the ignorance but tangent space normal map means that it may be good for 3dgs?
The model ( the usual mutant ogre) to whom I apply the shader , it totally smooth.

maybe you can show us the hi-poly model in your modelling software, and low-poly with a shader in gs?