NVidia Normal Map filter problem

Valandar

Okay, I started messing with the Nvidia Normal Map filter in Photoshop, and what comes out isn't a normal map at all - it's a flat greyscale image with everything moved to either 50% grey or solid black.

What am I doing wrong?

MoP

Use Crazybump instead!

These days I only use the NVidia filter to normalize Crazybump output, since it isn't normalized by default.

As for how to use the NVidia filter properly, try setting it's mode to "color space" on a single-layer greyscale heightmap. Should produce a decent normal map.

Valandar

Thanks, MoP!

Jarrod1937

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These days I only use the NVidia filter to normalize Crazybump output, since it isn't normalized by default.

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explain this in more depth please.

MoP

Tangent space normal maps consist of vectors relative to a polygonal surface, these vectors (X Y and Z) are represented in the red, green and blue channel - when normalised, these vectors all add up to 1. If they don't add up to 1, then the normal map is not normalised, and it may look odd when displayed (eg normals pointing in wrong directions).
Therefore the normal map should always be normalised before use, currently Crazybump doesn't do this, so the NVidia filter must be run over the output to bring the RGB channels back into line...

I'm sure a programmer could give a more sensible and coherent explanation, that's just how I understand it, admittedly I haven't read up much on the subject

Ben Cloward

Valandar,
Your describtion of the issue isn't very detailed here, but I think I've seen that problem before. It's a bug. I recommend that you send an email to the Nvidia address in the lower left of the filter control panel and tell them the steps that you took and the settings that you set that causes that to happen. The last time I submitted a bug about that tool, they fixed it the very same day and emailed me back my own personal version with the bug fixed. I was really surprised how responsive they were. I can't imagine it would be any different with you assuming you give them a good enough description that they can reproduce it on their end.

Eric Chadwick

Hrmpf. They used to be very responsive, before Doug Rogers left, I think that was November 2005. I've submitted bugs since then, but nothing ever comes back. I guess Ignacio has bigger fish to fry.

Yeah, just checked again. Their exe hasn't been updated since July 2005! Do you have something more recent?

Here's the latest I got. Some new features in both the normalmap tool and the DDS saver/loader...
http://boards.polycount.net/showflat.php?Cat=0&Number=115830&an=&page=0&vc=1