Bump Map Issue

This is driving my nutty…I am modling an aircraft and want to use Bump mapping (NOR) to have the panel lines on the aircraft slightly recede into the surfaces to give the look of realistic panels. I have created a bump map with a gray background (RGB, 128, 128, 128) and my panel lines are straight black. When I map it to the model and render I get mixed results…see the pic.

In circle A, the vertical fusalage panel lines are a little faded and dont highlight near as well as the horizontal fusalage lines.
In circle B, the horizontal panel lines fade away to nothing, and the verticals do not show at all. It seems the farther away from the camera the lines are, the less you see of them.
In circle C, the panel lines on the wings barely show up at all.

So my question is, how can I get consistent looking panel lines that recede into the surface slight (to create a highlight).

I’ve tried adjusting the NOR value and that helps some, but it causes the closer lines (to the camera) to get really ugly looking.

Is there a way to do this to get better results?
If there a better way to do this than using bump maps and NOR?


Try creating tangent normal maps instead of bump maps.


Hmmm…I’ll look into that…any tutorials on doing that out there?
Will that give me the highlight effect I am looking for?


Anyone have any ideas on how to do this? I tried tangent normal maps and actually got a worse result, so I am not sure if I did it correctly.


Attach a blend if you can. Pack any textures into the blend.


Blend file is attached. The bump map is packed. It only contains panel lines for the fusalage, but you can see when you render how inconsistent they are as they kind of fade away the farther away from camera they get. But even when I had the wing panel lines in the bump map, they barely showed up on the horizontal surfaces of the wings.

I am sure lighting has some play on how the lines look with NOR, but I wouldn’t think it would be that much. Go ahead and flip on the Normals button and then render…looks worse.

The bump map is 4000 x 4000 pixels, but I still get lots of jagged edges on the panel lines.

The file is compressed as well…is that OK?

Thanks for taking a look.


A Kate B5N2 v16 - Test.blend (254 KB)

The viewing anngle and light direction impact the effect of the normal map. The lines on the image seem to be only a pixel wide and will, and do give badly jagged lines. You have loads of wasted space on the 4k image. You can have multiple uv maps for objects (use search and view the blender.org wiki), try making another one for the fuselage that makes the most efficient use of your line image. They can be more than 1 pixel wide and give a smooth appearance.


Yes, the lines are 1 pixel wide. That is what many aircraft modeleres recommend and they get great results…see this post near bottom of post (http://blenderartists.org/forum/showthread.php?t=173558&highlight=bump+map&page=2).

I am not opposed to wider pixel lines if the result is better.

On the 4K image, I was going to put the wings, tail, fusalage bump map on one image (thus less wasted space). But after rreading the forum above, they also recommend breaking it up into seperate bump map images. Question, does the bump map have to be square (i.e. 200 x 200) or can it be rectangular? I know when you create in Blender it makes it square, thus wasted space. But can I crop it down and have it still map correctly?

Any luck getting a better result with tangent normal map?

DO NOT use .jpg images - it produces jagged lines - PNG recommended.
Uncheck MipMap under texture image tab - it causes blur/fade image details with distance.
In real, lines between panels have darker color ( dirt etc. ) - so you can use your bump map in color ( or reflectivity Ref ) channel just a bit to expose the lines.
To much bump causes unnatural look - panels doesn’t have rounded edges and must stick each other without any gap ( in theory ) so in shots from distance it’s better to use more color instead of increasing bump effect.

jawra - Thanks…the mipmap option worked wonders on the fading lines. The PNG format help somewhat on the jaggies.

Thanks agin for the help and expertise! :slight_smile: