Gimp Normal Map Plugin Problem (Solved)

I realize there are differences, but I’d like a normal map to act like a bump map so I could use it in game. How do I do this?

I start out with a bump map, and convert it to normalmap using the normalmap plugin in gimp. I apply it to my object and it looks fine, the parts that are supposed to be “pooping in” are, however, if I rotate my object, sometimes the parts that are supposed to be popping in look like they’re popping out. I don’t understand. If I use the bump map and render it in Blender, it always works right, but not when I use the normalmap. What am I doing wrong, or is this just a limitation of normal maps for some reason? I could understand that if it was mapped to world space or something, but it’s tangent.

For example, here is my object looking fine with the normal map (light is to the right of camera):


And here’s when I rotate the object 90 degrees, suddenly the bumps are popping out rather than popping in.


Here’s the normal map


The normalmap is UV mapped to the object and I am rotating it in object mode, not edit mode.

What’s going on?

I mean, I suppose I can adjust the normal map depending on the rotation of the item, but I wish I wouldn’t need to, plus how would it work on things like game characters faces which are changing direction all the time?

hmm… maybe the normal map is bad, maybe the gimp plugin doesn’t create usable results or maybe I’m not using the settings properly? I just baked a normalmap from the bump map in blender and it seems to be working. Hmm…

I figured it out. You need to select “Invert X” in the Gimp Normalmap plugin, but not Invert Y. I was selecting both, and that’s what messed me up.

Can you exlpan where youc an find this plug in and how to install and where this plug in for GIMP?

would like to test that

now don’t forget that a bump map won’t necessarely work at all angle
that’s a limitaton of normal map
Bump map shoud work better
then you go with displacement map for larger bumps!

happy 2.5

http://code.google.com/p/gimp-normalmap/

it should say on the site or in the download how to install it

i can see where you can download this plugin
in Help menu
but where do you find this plug in to download it i don’t see any lknik in there ?

THanks

Bump map shoud work better

uhm… no.

"Bump maps merely change the perceived height of the surface. The normal of the model still points in the same direction (i.e. light still bounces flat off the polygon, but some bits look higher up).

Normal maps actually change the angle that the surface points at, it gives a much, much more accurate and believable result and allows you to fake more complex forms than bumpmaps allow and better lighting on the surface (i.e. it actually changes how light bounces off the polygon, so a flat polygon can appear to have a curved surface)."

well that’s what i read in wiki page for normal
that it works well if at proper angle from camera view
and at other angles it does work well or at least less then when using a bump map!

is there other doc giving more technical detaisl and ifferences between thesee 2!

and also in 2.5 we have a better algo for bump map
but not certain how you set up normal map in 2.5
any example on this ?

see wiki here on of the phrase says that
In the low-poly model, this may be replaced with a single plane, oriented in the same direction as the detailed ear mesh
http://wiki.blender.org/index.php/Doc:Manual/Textures/Maps/Bump_and_Normal_Maps
it does say that for working palne has tob e oriented in the same directionas the original

but not for the bump map i think

happy 2.5

and at other angles it does work well or at least less then when using a bump map!

Doubt that.

Did you actually read the first part of your link? It says that normal maps are “much more accurate”, and the only drawback is they’re harder to generate.

it does say that for working palne has tob e oriented in the same directionas the original one
but not for the bump map i think

This part was talking about how to generate normal maps, from highpoly to lowpoly. A comparison with bump map wouldn’t make sense.

Sure, the improved bump in Blender works great, I’ll be definitely using it a lot. But to say bump is better than normal map, is just plain wrong.
But EASIER to create, yes…

for me in 2.49 with vid card i have i always had problems to make nice normal color map
don’t know why i even try the monkey in wiki and not working well

but have to test this in 2.5 may be it will work better then in 2.49

are there any good example we can download to test theses normal map in 2.5
with sample file and png normal map ?

happy 2.5