Blending Normal Map

Saidin311

Hello, first post here. I've been told these forums are a great resource for questions etc! I'm hoping someone can help me with this issue.

I have 2 normal maps that I would like on the same object. However when I use "overlay" in photoshop it washes out the colours a little and I seem to loose height in max.

I've experimented with adding a second bump in the normalBump area of Max materials to achieve the affect I want, however my ultimate goal is to bring the texture/material into Unreal Tournament 3 and I need a combined normal map because I don't know how to combine them in that editor yet.

The following are the 3 images. The first is the object normal (created from Max). The second is my scratches and bumps created in photoshop. And the third is the combination of the two using "overlay" in photohop.

Note that the third one the colours are slightly washed out. I think thats causing my lack-of-height issues.

Using the 3rd as my normal map just doesn't seem to have the same height affect as using just the first or just the second.

Jeremy Lindstrom

Have you tried multiply?

Nm... edited...

Saidin311

Forgive me, but I'm not understanding how to halve the blue values. I tried setting them to black and that just destroys the image?

Am I adjusting the saturation? The brightness? The levels? The colour balance? I just seem to be missing something?

Deleting the neutral pixels is something I didn't look at, although its not as clean of a solution as I'd like.

Ryan Clark

Hi, Saidin311

I've written a program to blend normal maps. It preserves data much better than a photoshop overlay. I think it's just what you're looking for.

I invite you to download the beta test from www.crazybump.com, and see if it meets your needs.

There is not much documentation yet, but just open the "normals mixer," and I hope you'll find the rest straightforward!

cheers,

-Ryan Clark

Ryan Clark

Here's your example, blended using CrazyBump's mixer, with both maps at 100%.

Along with a better blending operation, CrazyBump gives you sliders to adjust each layer, and a 3D preview.

Saidin311

I downloaded it and I'm quite impressed! Can't wait to try further things with it. Thanks for the help and the program. Now to figure out more material settings in UT3 to get it to look as good as it does in max, but in unreal.

Ben Cloward

If you're looking to do normal map blending in Photoshop, the easiest method is the one that Per128 described. While that method sort of works, a better method is described here:

http://www.projectoffset.com/blog.php?id=74

Just grab the action at the bottom of that page and run it on your normal map. Then paste your first normal map under the folder created by the action. This will give you much better results than the half blue/overlay method.

-Ben

Eric Chadwick

Cool find Ben!

There's a nice writeup of the Photoshop blend modes here.
http://www.simpelfilter.de/en/grundlagen/mixmods.html

Overlay basically Screens the bright background parts, Multiplies the dark background parts, then doubles the result.

Saidin311

Thats a great find! Thanks for that Ben.
And the writeup on Photoshop blend modes is a great read too. I'm not fully noob when it comes to PS, but its nice to read some technical descriptions to brush up on the knowledge.

In case anyones curious this is what the final texture turned out to be. I'm not quite happy with the amount of height, I wish there was more. But for a first run at creating a UT style texture I was happy.