X-Plane Normal Maps a.k.a. “_NML”
X-Plane Normal Maps a.k.a. “_NML” by Marc C. Leydecker a.k.a. Belga12345.
Who doesn’t know Marc Leydecker aka Belga12345 from his gorgeous modeled and highlight detailed airports like KFYJ (West Point) and KPVG (Hampton Roads Executive Airport). His airports are, no doubts about that, of an extraordinary quality and as real as it gets, but what has that to do with NML files or just normal maps?
I own, as many others, the Khamsin Studios Grumman HU-16 Albatross and during the writing of my review, I found this movie that shows the beauty of this well modeled aircraft by Khamsin and Hydroz. I not only like the movie, but in particular the N98TP livery. Gorgeous, at least, that’s what I find. Besides that Marc is a highly skilled airport developer and SketchUp guru, he’s also a skilled livery painter and since I know Marc now for a while, I asked him, after he released another Italian SAR Albatross painting, if it was possible to paint for me this awesome N98TP livery.
During the painting process, Marc inform me about Normal Maps or NML files and on behalf of Marc, I would like to share this information with you. This article is intended for those who start from scratch with NML file and perhaps, after you’ve read it, you would like to add something to it via a comment. As long as comments are “structured”, I’m quite sure Marc appreciates this. Curious, check out these exclusive N98TP screenshots!
In X-Plane an object has a texture file known as Object.png. That same object can have a night time texture and then it’s called Object_LIT.png. This texture can also have a Normal Maps file which is known as Object_NML.png.
So what is NML or Normal Maps?
An NML file is a combination of a Bump Map and a Reflection File. Sounds Chinese to you?
Let me give you an example …. you have a scratch on your car. When parked in the shade you do not notice it or at least, you hardly notice it, but when the sun shines on it, it is very prominent. This effect is called NML. In other words, when the aircraft is in the shade, you can barely see the rivets, but when the sun shines on it, they almost look like 3D.
Let me show an example, maybe that makes things clearer. The screenshot below is the wing of my Albatross.
The next screenshot thus below is the DEFAULT NML file of the aircraft for the US Coast Guard Albatross. Note the USCG writing on the right wing of the NML file.
On the following screenshot below the Albatross sits in partly shade and please take attention to the wings. See, you don’t see any writings on the wings!
But now, see below, the Albatross sits in the sun and surprise … notice the USGC writing on the wing! Can you remember, I showed you the DEFAULT NML file from the Albatross before.
I hope so else I’ve to find another way to explain it to you. An NML file certainly adds realism to the otherwise Tupperware looking aircraft. Think about it, a bare metal fuselage should reflect every sun-ray, but its pinstripes and markings shouldn’t.
So what’s the difference in-between a light gray texture and an aluminum texture? The answer is the …… NML file.
Even the above USCG example could be useful. This could have been a repaint of an ex-Coast Guard aircraft. In the sun, you can still see where the original markings where. Now be subtle! You do not want your rivets looking like they popped out 1ft in the sun. How do I make an NML file?
To be honest, I haven’t found any good tutorial. NVIDIA, the graphics card maker has released a NML plugin for Photoshop. With their tool, you can convert your plane texture to an NML file however, still a lot of fine tweaking to do. In this article I have been talking about planes but the same principles apply to buildings. Especially buildings with per example metal corrugated roofs.
Marc Leydecker (Belga12345)
March 21st, 2015