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View Full Version : normal mapping - clear thing up for me

TyKeiL
06-18-2003, 10:09 AM
now.!

normal mapping and bump mapping

i hear alot of people say
"is that normal mapping or bump mapping?"

now as far as i could tell, bump is a slang word for normal.. which MAX users use cause there brought up saying the wrong things cause of the lack of standards for things in the 3d design world.

now i know what people mean when they Refer to normal mapping..

which is the process of baking the normals of a high poly model onto a texture for the use in a low poly model, to make the low poly model look smoother than it reALLY IS.

RATHER THAN RELYING ON THE NORMALS OF THE SEPERATE SMOOTHING GROUPS IT USES ITS OWN TEXTURE DRIVEN NORMALS ALTERING THE WAY THE LIGHT REACTS WITH THE SURFACE

NOW.

I THOUGHT THAT BUMP MAPPING WAS.
THE USE OF A TEXTURE TO CREATE BUMPS THROUGH MODIFYING THE NORMALS OF THE POLYGONS THROUGH TEXTURES, ALTERING THE WAY THE LIGHT REACTS WITH THE SURFACE

HENCE NORMAL MAPPING = BUMP MAPPING

SO NOW I SEE POEPLE ALL AROUND USING THE TERM NORMAL MAPPING TO DESCRIBE A PROCESS OF THAT BAKING PROCEDURE FROM HIGH POLY TO LOW POLY

NOW AM I TO LEAVE THIS SUBJECT ALONE AND LET THE LANGUAGE CHANGE?.

OR DO WE FIND A BETTER TERM FOR THIS SO CALLED "NORMAL MAPPING"

SUCH AS NORMAL BAKING

SO SOMEONE CAN ASK..
"DID YOU BAKE THOSE NORMALS?"
INSTEAD OF THE POINTLESS QUESTION OF NORMAL MAPPING VS BUMP MAPPING BECAUSE THEY ARE ESSENTIALLY THE SAME THING

OR DID I SOMEHOW MISS SOMETHING WHEN I READ A 4 PAGE POST DESCRIBING WHAT "NORMAL MAPPING" WAS VS THE BASIC BUMP MAPPING WHICH ALSO USES THE MATHAMATICAL CRATED NORMALS BETWEEN FACES

CAN A PROFESSIONALPLEASE TEL ME TO SHUT MY MOUTH OR SAY "I AGREE THAT PEOPLE ARE MISUSING THE TERMINOLOGY BUT HEY !WHAT CAN YOU DO?!!!"
THANKYOU
EVIL
06-18-2003, 12:55 PM
caps!
metal me solid
06-18-2003, 01:01 PM
lmao- didnt otice that Oo;;;
TyKeiL
06-18-2003, 01:09 PM
lol!!.. sorry for th headach for anyone reading the post

i deleted all of my fonts well as much as icould after i installed civilisation play the world as they screwed up my menu's in all of my programs they are all 1/3 times bigger now

and the font that took over as the default font kind of doesnt have any lower case

so yeah sorry for the inconvenience
stevej2k
06-18-2003, 02:36 PM
Have a read of this page.

http://members.shaw.ca/jimht03/normal.html

its has some very nice background info. it talks about the limitations of 'bump maps' and how these differ from 'normal maps'


In summary *extracts from the linked page* . "bump maps" only store Height information in shades from black to white. The engine can use this information to render highlights and shadows on a surface based on where the light in the scene is. The limitations of "Bump maps" is that engine is restricted in showing the surface transitions in elevation only, meaning that the surface itself appears flattend, and not protraying correctly the depth the artist was trying to express.

Fine details get blurred out of the bump map render, because a single pixel contains no real data of its own - it is only in relation to its neighbors that it has any meaningful information. A 100% white height map renders exactly the same as a 100% black height map. A game engine looking at a height map has to take a sample of a certain radius around each pixel to determine if this pixel is the same relative to its neighbors, or sloping up, down, to the left or to the right, before it can rendering the shading on that surface. This sampling slightly degrades the detail that can be portrayed with the height map.

While a height map *bump map* only contains 1 plane of information - the "Z" (height) plane, a normal map contains 3 vectors of information - "X" direction, "Y" direction and "Z" direction. Thus, each pixel in a normal map encodes which direction that particular point is facing - the "normal vector" of the surface. Each pixel in a normal map has meaningful information, so details can be rendered more crisply than with bump maps alone. This allows modern game engines (Doom III) to more realistically portray the lighting on a surface. A properly constructed normal map can fool the eye into perceiving much more complex 3D geometry on a simple surface. Theoretically, normal maps on a cube can make it appear spherical, at least in terms of shading properties (the outline remains unchanged).


I guess you could say that "normal maps" are the next generation of "bump maps"

i hope at least some of this helps. :shrug:
TyKeiL
06-18-2003, 03:13 PM
yep cheers,
idefinatly clears up the difference between a "bump" map 1 channel
and a "normal" map 3 channel

i still think of them both as normal maps but at least i wont go around spouting bullshit to people when i feel like a rant:p
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