I'm having a problem converting a normal map to a bump map using the nVidia Texture Tools 2. I've used the Tools to create hundreds of normal maps with no problem, but the other way around doesn't seem to work. According to the manual "-toHeight: create a height map (source is a normal map)". There's no error message; it just doesn't create a new file (I've tried a variety of options, including several -output options).
I need to modify an existing complex normal map. The most straightforward way is to convert it to a bump map, modify the grey levels as necessary, then convert it back into a normal map. I was hoping to be able to do this without purchasing CrazyBump.
Has anyone successfully used the -toHeight option with the Texture Tools?
I've never used TT2 for this, but i thought i should mention a few other things:
The nVidia and xNormal plugins can also convert normal maps to something of a greyscale heightmap, but the output is a really poor image on both accounts; certainly not something you'd want to turn back into a normal map. The biggest flaw in the process that I've seen, is that there's a constant gradient from one corner to another across the whole image.
I don't have paint.net installed right now, but i'm pretty sure you can isolate the RGB channels. Small tweaks can always be done this way. Also, blending normal maps is a snap, check http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm out. The blending info is about halfway down the page. I know it's for photoshop, but the ideas are pretty universal, just depends on the channel control.
http://www.katsbits.com/htm/tutorials/obli...derstanding.htm
Here's a link for everyone to see how Oblivion used parallax mapping which is not a true parallax map. This is important to read if anyone is goes to edit meshes to use a parallax map.
I'd just like to point out that the writer doesn't understand what s/he is talking about, and is chock full of misinformation. Sorry if I sound like I'm looking down my nose with that, but I've always put a lot of effort to making sure that I put out good information when I help people. But that article has just given me a serious case of facepalm.