I've just found a super easy to use program which makes all your normal, occlusion, displacement, specular, and diffuse maps instantly. You have full customisation of all the detail levels and settings in each map, plus it renders them all onto the object of your choice so you can see what it looks like together. It is only a 30 day trial, but it is definitely worth getting if you make a lot of maps like these.
CrazyBump

Theres a video on the site which describes it perfectly, but i'll give an example texture which i used: EDIT:Sorry, didn't realise the texture was so big. Feel free to use it by the way. I found it free online.

http://www.gametoast.com/forums/viewtop ... mp#p301725

It does have its own limitations, as mentioned by AceMastermind a few posts down.

Man, this is great. I would like to know how to apply this to a model, though.

with xsi and without

you can only apply normalmaps though, no specularmaps

Ok, I will have to mess around with XSI, I recently downloaded it and am beginning to learn.

Maveritchell wrote:http://www.gametoast.com/forums/viewtop ... mp#p301725

It does have its own limitations, as mentioned by AceMastermind a few posts down.

Oops. Sorry, i didn't know about that. I'll have to have a look at that free program Ace mentioned...

xNormal works fine too, and is free.

There is a normal map plugin for GIMP.

nVidia released a Normal Map plugin for Photoshop 6-CS5.

However, for High Visibilty assets like 1st person models or Characters, nothing beats making a Hi-Poly and baking down to a low-poly. You get more control over detail and a cleaner normal map. Generating normals from Photo source textures is generally good for large area textures or for use in large environments. It's also used allot when a large amount of props need to be done in a short amount of time.

INdeed, I've read that quite a lot of companies have used this tool create the mayority of their environments (mountains etc.) from photographs, or sometimes they paint the basic texture and generate a diffuse, normal, specular and maybe even a parallax map from it through this tool.

IOW; it is quite professional.