Bump, Displacement and Normal maps!
|29 min read
ken1171's avatar
By ken1171   |   
11 21 7K (1 Today)
Published:

Visitor Map
Create your own visitor map!




** Bump, Displacement and Normal maps! **

       

           

There seems to be a considerable level of confusion about what's the difference between bump, displacement and normal maps, and even some dispute about which is better. People ask me about this so often that I have decided to make the whole nine yards clear in one place. Let's cover all 3 kinds of maps right here! But before I cover each in detail, let's remember that they all serve the same purpose, but in different ways. ^___^

Let's start with the simplest first. Bump maps are 8-bit greyscale maps that add bumpiness to 3D surfaces. And by 8-bits, I mean the greyscale maps can only use up to 256 levels of grey, which limits the smoothness of the results. But wait, there is more - bump maps can only represent bumps in a single direction, perpendicular to the surface. In other words, in the direction of the surface normal vector. This is like up and down only.

In addition to these limitations, bump maps do not really change the geometry shape. It instead fakes it by means of mathematically changing the face's normal vectors to cause fake shadows that simulate the presence of bumps. So the effect depends on lighting directions, and cannot be seen from outlines of the 3D model. So even if the model may appear to have bumps, its silhouette will remain perfectly smooth. It can fool the eyes in one way, but not the other. The math to calculate the normal face vector direction has some level of impact on rendering times.

Displacement maps work in a completely different way. They actually displace the geometry (hence the name) to create physical bumps instead of faking their shadows. What kind of geometry can be displaced depends if the rendering engine supports (or not) microface displacement. If it does, even a single face can be greatly detailed with a displacement map, even if it doesn't have the sufficient geometry to do it. If it doesn't, the geometry will require a lot of additional faces to be able to produce the level of detail required by the displacement map. In general, displacement maps require considerable computer power to process, so they impact rendering performance considerably.

Now let's cover normal maps. These are the newest technology in the bunch, and again, works in a completely different way. There are basically 3 types of normal map: object space, tangent space, and MikkT space. Older rendering engines such as Firefly and 3Dlight use old school tangent space, and Poser also supports object space. Which one to use depends on what you want the model to perform.

Object space is used on static models that don't bend or deform, like 3D props. Now tangent space is used on organic models that bend and deform, like bone-rigged characters. So far, so good, but tangent space has issues when dealing with mirrored geometries, like the other side of a shoe/boot, the other hand of gloves, or the other side of the body. It will display the effects of the normal map inverted on the mirrored side, and there is nothing you can do about it.

On a practical side, normal maps are also fake detailing like bump maps, but they have 2 major advantages. First, it can use millions of levels as opposed to only 256 from bump maps, which create much smoother results. Secondly, it can represent displacement in all 3 directions (x, y, and z), which can produce much more detailed results than bump. It does that by storing pre-calculated 3D vectors info encoded into the RGB color space of a bitmap file, so the results of all the calculations are already stored and ready to use, like a LUT (look-up table).

This makes normal maps much faster and efficient than bump maps, and that's the reason they are the option of choice in real-time game engines. They render faster, the results are smoother and more detailed. But they are still fake details, so the details won't show in the model's silhouette. Like bump maps, the effects can only be seen from certain angles, and depend on the scene lighting.


           

Now back to the issues with old tangent space, modern rendering engines like Octane, Iray and Cycles use a new normal space mapping called MikkT, which is the modern standard. It automatically compensates for mirrored surfaces, and displays the results correctly. Firefly and 3Delight don't support, and will never support MikkT for backwards compatibility reasons. That would fix the mirrored geometry issues, but would break everything that was already made for the older version, so it's a no-win in either cases.

The problem is having 2 rendering engines in both Poser and DS, where one supports only tangent space and the other MikkT, which causes a compatibility issue with normal maps. You can't make a material that will work properly in both. The green RGB channel in MikkT maps are inverted comparing to the same map using tangent space, and tangent space cannot handle mirrored geometries, while MikkT can.

We can use shader nodes in Poser to invert the green channel and reuse a tangent space normal map in Cycles, and perhaps do the same in DS using ShaderMixer bricks. The important is to know that these differences exist, and where. But the fact is that normal maps are way more modern, efficient, and versatile comparing to bump maps. Displacement is the only of the 3 that actually creates new geometry, while bump and normal fake it. Nonetheless, displacement is the most computationally expensive of the bunch, so it's the slowest to render.

Normal maps, conversely, are so fast to render that many programs can show their full effect in real time, like Poser previews when hardware OpenGL acceleration is enabled, assuming your video card supports that. All modern game engines support displaying normal maps in real-time. As seen above, there are indeed some compatibility issues, but it's still the best option performance-wise.

Although displacement maps are the slowest from the bunch, modern nVidia video cards that support DirectX 11 can use the massively parallel power of the GPU to hardware accelerate displacement in real-time using micro-displacement. A few AAA video games take advantage of this, and it can make a huge difference in the final visuals. It can take a single face and detail it to your heart's content using real displacement instead of fake bump or normal maps.

So these are the options, how they work, and what they do. There are some pros and cons for each one, and many rendering engines support using both bump and normal maps at the same time (like Firefly), affecting the same geometry.


           

Hope this helps clearing out the confusion regarding these maps, and help you make your choice next time you need them.


       





Clubs I joined:
:iconposeraddicts: :iconcatgirl-zone: :iconkawaii-neko-club: :iconglossy-legs-club: :iconpantyhoselovers: :icon3danimationgroup: :icontradewinds3d: :iconpanoramaclub: :iconworld-of-catgirls: :iconanime-manga-artists: :iconflanimate: :iconfemale-incorporated: :iconbrazilians: :icondarkskin-love: :iconsexyvoluptuousvixens: :iconhouse-of-fetishes: :icondawn-of-a-new-era: :iconpwfa:

MY PINUPS:

Mature Content

-75K Strip Kendo Club- by ken1171
-Silent Red Shadow- by ken1171 -Lady blues- by ken1171
-Pool is fun- by ken1171

Mature Content

-Smoking hot and wet pinup- by ken1171
-Madoka 2 Preview- by ken1171
-Bazooka Cowgirl- by ken1171 -103K Sexy Tribal Princess- by ken1171 -I want you- by ken1171
-101K Big Booty Special- by ken1171 -Sexy Golden Rider- by ken1171 -Sexy ice cream- by ken1171
-79K Sexy Veyron- by ken1171 -TradeArt for Stalfoss II- by ken1171 -Sexy Pink- by ken1171

MY ANIMATIONS:
-How to Catch a Girl- by ken1171 -Daydream- (Animation) by ken1171 -64K Sexxxy Ryn Kiriban- by ken1171
-108K Sexy Vicky Walk- by ken1171 -Sexy Fantasy Kaori- by ken1171 -Funky Sexy Girl- by ken1171
-54K DOAX Hitomi Kiriban- by ken1171 -Pixie walks her dog- by ken1171 -Running Huuki- by ken1171
-Night Run Animation- by ken1171 -But isnt that stupid- by ken1171

MY COMICS:
-Nonsense is in Fashion- by ken1171 -Master Usajiro ep01- by ken1171 -Master Usajiro ep02- by ken1171
-Pirate grudge- by ken1171

Mature Content

-Private Study- by ken1171
-Creature comforts- by ken1171

MY PANORAMAS:
-87K Watson Lake, Arizona- by ken1171 -Jerome, AZ- by ken1171 -Mojave Desert, Arizona- by ken1171
-Oklahoma Beach, NY- by ken1171 -Fain Park, Arizona- by ken1171 -Quailwood Park- by ken1171

MY WRITING:
-Metal Seduction- by ken1171 CollectionsCollections
Chances are that nearly everybody likes collecting things during their life. My mom collects dolls from different countries, my friend collects stamps, another one collects buttons and so on. I collect Anime videos and have been doing so for over a decade now.
But the funny thing is that those collections only have a meaning to us. You might have a grandparent who passed away and left their own collections of something behind, and your family doesn't have a clue on what to do with it. If it's valuable maybe it can be sold. If not, it will either be dumped somewhere or donated to whoever might want it.
My wife and I went to some antique shops the past weekend and I couldn't help noticing how many meticulously preserved collections we found there. We found things of all sorts, like Coca Cola collectables from the 1950's and classic car miniatures from the 1960's. I remembered some of those things from my childhood (I was born in the late 60's) but never imagined someon
-Inaho's Homework- by ken1171
ShadoGal Mai Chronicles IShadoGal Mai Chronicles I: Living Forever
There are many vampire stories based on the fact that life loses its meaning if you cannot die. Those stories tend to emphasize that life itself can become a burden in such cases, because after a few centuries there is nothing much of new to be seen or learned, especially because history tends to repeat itself over and over.
That's how I defined the personality of ShadoGal Mai, my wacky half-vampire (damphyr) character. One can become quite bored after living for 500 years, and many books and movies have covered aspects of it, such as "Interview with a Vampire" and "Highlander". But in those stories the characters were nearly all male, and I here I wanted to show a female side of the story.
Human nature dictates that we will value the most what we don't have, or things that are rare and thus, precious. But immortality makes life itself worthless. In a vampire perspective life has advantages, although they have to live without a good deal of the
ShadoGal Mai Chronicles II====================================
ShadoGal Mai Chronicles II: Fay and the Scroll of Dhakr
====================================

One thing to keep in mind is that Mai us a supernatural being. She inherited a vampire hypnotic gaze that can paralyze humans with ease. After a "love bite", they become addicted to her highly arousing ways and will tend to come back for more at regular periods, which is very convenient for both sides. It's like the next step in the vampire symbiotic evolution, which is described in the "Unification Prophecy".
Mai doesn't like fighting and in most cases she never has to. That's the nature of vampires. She can paralyze any human just by looking at them in the eyes, no matter their physical strength - the gaze paralyzes a human (or even animals) by freezing their souls right at the core. Besides that, Mai has the strength of 10 men, which means trying to defeat her by brute force is unlikely to work by all means. It's not physical strength, but rather a
ShadoGal Mai Chronicles IIIEpisode III: Dawn of the Ancients
Fay was sitting comfortably on a sofa in this magnificent mansion. She was used to be at different places every once in a while, because her job forces her to move from place to place every few decades. There were five men around her, looking very suspicious of the new location. The older one, Vance, was particularly uncomfortable with the place because it has too many windows. He was not concerned about his privacy or anything, but instead about his own safety, since sunlight can be quite inconvenient to most vampires – especially the older ones.
They spent the following hours painting all of the windows black, and only then Vance could finally sit and rest on the large and decorated sofa where Fay had already fell asleep. How long has it been since the five of them have been faithfully following this woman? It becomes hard to keep track of time in terms of human years, since numbers in that system can quickly grow large. Vance thinks to himsel

-ShadoGal Chronicles IV-~ShadoGal Chronicles~
Episode IV: Legend of the Primal Princess

Legend claims the queen of the extinct race of the "Ancients" had four beautiful daughters, where the youngest was Mai (500 years old) and the oldest was Sethalus (8,000 years old). None of the girls knew of each others existence or of their significance on the events to come. As far as they know, they are the only ones of their kind although deep inside they want to believe there are others. Vampires have mixed feelings about them because they are not harmed by most of the common things they fear, such as direct sunlight and holy objects. The girls have become outcasts of both human and vampire societies, often seen as abominations. To some others, they are perhaps the answer to a long forgotten vampire prophecy that foresees the return of the "Ancients", from whom legend says the first vampires descended from.
With her fixed bat wings and pointy ears, Sethalus can walk in broad daylight and even eat human food. Ev
-Fatal Delivery- by ken1171 -A bird? A plane? No, it's...-
~A bird? A plane? No, it's...~
PART I:
One of the advantages of being 500 years old is that you have probably already seen it all. ShadoGal Mai was in a trip to the Big Apple when she spotted an interesting male figure flying in cape & tights over the city - but without any wings. Well, Mai has many superhuman powers, but flying without wings is certainly not one of them. Even less at speed! Very curious, She followed the man in tights until he landed somewhere in the streets. He apparently found somebody in distress and went down to help. Mai was very impressed by him: how can he have so much strength? Dad said I can't go out with human pets, but what about him? He can't be human!
PART II:
Mai followed the guy in tights until he went back home. As she hid inside his house, she sneaked around until she found the perfect opportunity to give him a little surprise 'love' bite from behind. Mai used her inherited vampire powers to keep the guy still while taking a sip. She immediately notic


MY FANART:
-Yuna Fanart- by ken1171 -What are you looking at?- by ken1171 -Bleach Orihime fanart- by ken1171
-54K DOAX Hitomi Kiriban- by ken1171 -Street Fighter ChunLi Fanart- by ken1171 -More Space Angel 80- by ken1171

MY ORIGINAL MUSIC:
-If Penguins Could Fly- by ken1171 -Techno Heavy Metal Revolt- by ken1171 -27,000 Exotic Journey- by ken1171
-Madoka Memories- by ken1171 -Bouncy Piano- by ken1171 -98K Rockit Bunny- by ken1171
-Heavy Metal Kitty- by ken1171 -Bluish Metal- by ken1171 -Gimme da Blues- by ken1171
Comments21
anonymous's avatar
Join the community to add your comment. Already a deviant? Log In
RAMWolff's avatar
RAMWolffHobbyist Digital Artist
Thanks Ken. 

Wondering about displacement.  When you mentioned mirrored in 3Delight do you mean if a obj is mirrored on one side?   So say one is working with Dawn, do you mean one side of Dawn is mirrored rather than just created symmetrically?  I seem to be confused about this a bit.  I like and always have preferred Displacement but if it's going to act up like that I guess Normal is the way to go but in DS there is no slider for Normal maps to control the amount of it used like in iRay, which has a level of detail slider....
ken1171's avatar
ken1171Professional Digital Artist
Symmetry only goes bad if the geometry is split into left and right separate geometries like the other foot of shoes, or the other hand of gloves. The other side of the body is still the same geometry, so the UVs don't get inverted. Nothing to worry about there. Since mirrored geometries have their UVs inverted, all maps will be affected, not just bump or normal. They all get inverted.

Unfortunately we still can't control normal map intensity in DS, unless when using an external renderer like Octane, Lux or Iray. These have their own materials and support modern MikkT mapping, which is not affected by inverted UVs.
WickedPrince's avatar
WickedPrinceHobbyist Digital Artist
Cool, so that explains it all. Thanks. :)
ken1171's avatar
ken1171Professional Digital Artist
Everything is simple once we know it. ^^
WickedPrince's avatar
WickedPrinceHobbyist Digital Artist
Eeeeyup. :)
Y-Phil's avatar
Y-PhilHobbyist Digital Artist
Many thanks for that so valuable information :aww:
ken1171's avatar
ken1171Professional Digital Artist
You're very welcome, and I hope it helps. ^^
Y-Phil's avatar
Y-PhilHobbyist Digital Artist
Sure :bow: :aww:
veryoldoldold's avatar
thank you, very clear and succinct!
ken1171's avatar
ken1171Professional Digital Artist
Hope you will find it useful. ^^
hiram67's avatar
hiram67Hobbyist Digital Artist
molto utile come sempre. Io uso Poser ma la rendo, li faccio con Octane. Creo la seconda pelle e aggiungi il bump map in grigio o bianco e nero. Quando si carica questi nella stanza materiali, ho Fleg Spostamento, in seguito al lancio di Octane di rendering. Il risultato finale sembra soddisfacente, non certo paragonabile ad un personaggio body.
ken1171's avatar
ken1171Professional Digital Artist
This seems to be one of the most misunderstood topics, so it was worth explaining it here - even if just to help me with having to answer the same questions over again. ^^
hiram67's avatar
hiram67Hobbyist Digital Artist
I agree with you
ibr-remote's avatar
May I link this to the Official Poser Forums run by Smith Micro, please ?
ken1171's avatar
ken1171Professional Digital Artist
Sure, why not? ^^
ken1171's avatar
ken1171Professional Digital Artist
Hope people will find it useful. ^^
ibr-remote's avatar
OK ! Thanks for permission !
ken1171's avatar
ken1171Professional Digital Artist
^^
ibr-remote's avatar
Thanks . Excellent.
ken1171's avatar
ken1171Professional Digital Artist
^___^=b
anonymous's avatar
Join the community to add your comment. Already a deviant? Log In