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View Full Version : Normal map vs bump map (done to death?)



clagman
10-29-2008, 01:01 PM
Hey all. I've been experimenting with normal maps and I say, pretty cool. I have seen some normals made from paint programs and I suppose I don't see the point of creating normal maps that way since paint programs are 2d.

I tried some experiments and I can't really see any difference between them. So what the deal with all the conversions to normal maps I see lately, where is the advantage?

3DGFXStudios
10-29-2008, 01:35 PM
did you apply you normal maps in the bump channel??? You need to do it with a normal node in the node editor.... for instsance

clagman
10-29-2008, 02:38 PM
Ya it really doesn't make any difference to my eyes. UV mapped surface with bump applied to bump or normal map applied to normal in node editor results it the same. Now normal maps generated from geometry, huge difference, but from 2d program like Photoshop doesn't seem to matter (using the Nvidia plugin). I keep hearing about how normal maps are superior but I don't seem to be getting it, at least not for this. Any suggestions or advice?

Sensei
10-29-2008, 05:13 PM
Normal maps are UV mapped images with constant resolution, bump map can be procedural texture computed at rendering time with infinite resolution dependent on camera zoom. Bump maps are converted to normal maps by GPU, CPU, or by user. Normal maps are faster to render than procedural bump maps, because of lack of conversion and finite resolution.

Captain Obvious
10-29-2008, 05:42 PM
Normal maps can potentially contain more data, since you have three channels instead of just one. For example, using a normal map to make a flat surface appear to have a slope is very easy. With a bump map, it is more difficult. Basically, bump maps have few disadvantages compared to normal maps for high-frequency details. However, for larger-scale stuff, normal maps tend to work better.

Mr_Q
10-29-2008, 06:33 PM
Properly normal mapped polys look incredible. Bump cannot even come close. It's the difference between a look that has 3D apparent surface properties versus jump a subtle bump.

I use Shader Map Pro to convert color textures all the time to normal maps and apply them in the Node Ed. Amazing. It now generates Ambient Occlusion as well. I almost don't need to raytrace anymore!

The image below is a great example the illusion of a 3D surface normal mapping and occlusion mapping can achieve

Auger
10-29-2008, 07:28 PM
Looks like a worthwhile twenty bucks!:thumbsup:

warmiak
10-29-2008, 07:45 PM
Properly normal mapped polys look incredible. Bump cannot even come close. It's the difference between a look that has 3D apparent surface properties versus jump a subtle bump.

I use Shader Map Pro to convert color textures all the time to normal maps and apply them in the Node Ed. Amazing. It now generates Ambient Occlusion as well. I almost don't need to raytrace anymore!

The image below is a great example the illusion of a 3D surface normal mapping and occlusion mapping can achieve

This looks to me like parallax mapping ...

caesar
10-29-2008, 07:54 PM
This looks to me like parallax mapping ...

Me too...

I use CrazyBump for generating bump/normal/displacement maps from images...very fast and has a awesome OGL preview.

dwburman
10-29-2008, 11:01 PM
I imagine what you're trying to do in the 2D paint program will have a big impact on the results. The attached picture is a NM made in Photoshop (I'm assuming it was PS) and can be found in the tutorial at this link:
http://www.paultosca.com/makingofvarga.html

The tutorial covers Normal Mapping pretty thoroughly and is worth reading.

clagman
10-30-2008, 08:52 AM
Mr_Q, I wonder what the software you are using does differently from Photoshop/Nvidia. I did some more experimentation and I can see that the self shadowing is superior with normals and I do seem to be able to obtain a smoother result (sometimes bumps are jagged and require a LOT more resolution than the normal), however I cannot get close to the level of your example without using displacement no matter what amplitude or height level is set. Whats the secret?

silviotoledo
10-30-2008, 02:30 PM
Normal Map does a big difference in terms of quality to your model.
Anyway, it's just a Shadow effect like bump, pbut more powerfull.

I mean it's also necessary to combine with bump maps, sometimes, wich is also a fake relief effect using shadow.

The main difference is that Normal uses R G B collors to displace X Y and Z, so you have 3 combined informations on normal while in bump you have only one.

clagman
10-30-2008, 02:36 PM
I'm starting to get there. I do see a pretty big difference in quality when up close or when it calls for more definition. Even when converting a bump the quality is much improved. I'm sold!

Captain Obvious
10-30-2008, 06:50 PM
Mr_Q, I wonder what the software you are using does differently from Photoshop/Nvidia. I did some more experimentation and I can see that the self shadowing is superior with normals and I do seem to be able to obtain a smoother result (sometimes bumps are jagged and require a LOT more resolution than the normal), however I cannot get close to the level of your example without using displacement no matter what amplitude or height level is set. Whats the secret?
There is no self-shadowing with normal mapping OR bump mapping.

Normal mapping can't really do anything that's impossible with bump mapping, because bump maps are converted on the fly to normal maps anyway. Converting a bump map to a normal map with a Photoshop plugin will not yield better results than just sticking it in the bump channel in Lightwave.

Sensei
10-30-2008, 07:05 PM
however I cannot get close to the level of your example without using displacement no matter what amplitude or height level is set. Whats the secret?

He has ambient occlusion shader baked to RGB texture...
It's something like: use high poly displacement with nice normal map, apply occlusion, bake it to image, undo everything to flat original geometry..

warmiak
10-31-2008, 12:26 AM
He has ambient occlusion shader baked to RGB texture...
It's something like: use high poly displacement with nice normal map, apply occlusion, bake it to image, undo everything to flat original geometry..


You are not going to get anything like that with just baking.

He clearly uses some sort of parallax mapping.

clagman
10-31-2008, 08:56 AM
I dunno, even converting images that were being used as bumps to normals I can see a difference. Maybe because the normal map is processed as RGB?

warmiak
10-31-2008, 10:49 AM
I dunno, even converting images that were being used as bumps to normals I can see a difference. Maybe because the normal map is processed as RGB?

Actually it shouldn't matter because a typical bump implementation will basically calculate an equivalent of normal map during runtime.

So basically, the only difference between normal maps and bump maps is that the former require 3 values and the latter only 1 value ( basically one channel ) and the other two are calculated during runtime.

Captain Obvious
10-31-2008, 11:03 AM
He has ambient occlusion shader baked to RGB texture...
It's something like: use high poly displacement with nice normal map, apply occlusion, bake it to image, undo everything to flat original geometry..
In the example image posted, with the radio or whatever? That looks like just a baked normal map to me... I can't see any parallax mapping or ambient occlusion or anything like that.

warmiak
10-31-2008, 11:08 AM
In the example image posted, with the radio or whatever? That looks like just a baked normal map to me... I can't see any parallax mapping or ambient occlusion or anything like that.

Well, I was referring to this one ...

http://www.newtek.com/forums/attachment.php?attachmentid=65263&d=1225326923

:)

clagman
10-31-2008, 11:49 AM
Maybe the internally calculated version is inferior to the pre calculated version using the Nvidia (or other) software? Just a thought, I can clearly see the difference between the two.

Auger
10-31-2008, 12:04 PM
What's the NVidia software called? Can't find it on their site.

clagman
10-31-2008, 12:30 PM
That one is available at http://developer.nvidia.com/object/photoshop_dds_plugins.html
Much faster than working the light direction individually.

Captain Obvious
10-31-2008, 06:36 PM
Well, I was referring to this one ...

http://www.newtek.com/forums/attachment.php?attachmentid=65263&d=1225326923

:)
Ah, yes, that's obviously not just normal mapping.

Auger
10-31-2008, 06:53 PM
That one is available at http://developer.nvidia.com/object/photoshop_dds_plugins.html
Much faster than working the light direction individually.

Thanks clagman, I'll check it out.