Normal Map from HeightMap calculation - theory/source ?

Just calculate normal (x,y,z) for each pixel in heightmap, and then store x,y,z coordinates in normal map texture. Or just store x and y in normal map texture and calculate z in pixel shader.

I still had this lying around somewhere on my hdd, so I'm afraid I don't know the source.
It basically calculates two tangent vectors, and obtains the normal by doing a cross product of both tangents.



IIrc this looks a bit more "blocky" then running the heightmap through the nvidia photoshop plugin.
I'm pretty sure that I read about using a sobel filter to get rid of the blockyness, but I haven't tried that yet.

Quote:

Original post by Hyunkel I still had this lying around somewhere on my hdd, so I'm afraid I don't know the source. It basically calculates two tangent vectors, and obtains the normal by doing a cross product of both tangents. *** Source Snippet Removed *** IIrc this looks a bit more "blocky" then running the heightmap through the nvidia photoshop plugin. I'm pretty sure that I read about using a sobel filter to get rid of the blockyness, but I haven't tried that yet.

You should normalize the result.

Indeed, all normal vectors should be normalized at all times.
I wonder if I forgot to do so when I tried this the first time.