Bump map, normal map and displacement map

User avatar
Marcel2586
Posts: 438
Joined: Sat Mar 05, 2016 7:42 am

Bump map, normal map and displacement map

Postby Marcel2586 » Sat Apr 23, 2016 12:37 pm

Bump map
Bump maps work only with greyscale to provide either up or down information.

I try to simplify a bump map
See a bump map as water.
black is 0 percent water and white is 100 percent water.
Now take a glass and pour black in it. (0% water, the glass is empty)
Now pour dark grey in it. (25% water in the glass)
Now fill the glass to grey (50% water in the glass)
Now fill the glass to light grey (75% water in the glass)
And now fill it to white (100% water in the glass, it is full)

water example.jpg
water example.jpg (29.09 KiB) Viewed 9595 times

This is the basic how a bump map works.
black is no bump and white is full height all the shades of grey are calculated as height.

bumpmap.jpg

This is the picture i used on a simple plane

Here the result, only bump map added
plane bump map.png



Normal map
Normal maps are bump maps on steroids.
It holds more information in it on all axis.
It gives you high detail on low poly objects.
Next-Gen game consoles rely heavily on normal maps.
next gen consoles.jpg


You have two kinds of normal maps.
1: Tangent Space normal map. the most used in Poser and Studio. It is a mixture of purples and blues.
This is very good for animations and characters.

2: Object space normal map. This is a mixture of rainbow colors and is a little bit more advanced.

Here the two different normal maps
normal maps.jpg


How does normal maps work.
In a normal map all the heights and depths are stored in the RGB and is translated into X, Y, Z axes.
So basically it tells how much water is there in the glass and is it a glass, bucket, or swimming pool. This is not completely true, but it is very near.

bumpmap_NORM.jpg

This is the normal map used

Here the result, only Normal map added
plane normal map.png


displacement map
The displacement map works in a similar way as a bump map, but this time it gives real physical depth.
A displacement map can be baked from an object or like a bump map made from an bitmap. Normally the bitmap will be 8 bit, but this is actually not so good for a displacement map.
The higher the bits, let’s say 16 bit or even 32 bit. The render will benefit from the detail of your displacement map.

Displacement Mapping is very much dependent on the amount of polys in the mesh, a high poly mesh will give better results & more detail than a low poly model. Unless use of such things as "Sub-Poly Displacement" (called Micro-Facets in Reality) which subdivides the amount of polygons during render time giving the appearance of more polys in the model than there actually is. (Thanks Fuzzy70, for clearing this out)

But is displacement mapping the holy grail? No it is not. Displacement is hard on your system when rendering. But if you use it, it will definitely pay of as the surface is transformed. That will bump maps and normal maps never do, they are just shaders telling the light how to bounce of the surface. that's why the borders never have depth. (look at the examples from bit map and normal map)
If you use only, lets say, normal maps for a wooden floor with only a top light, your normal map will have a real problem. it shows flat all the way.
It needs angle light to work.

Here the result, only displacement map added
plane displacement map.png


Using These Maps Together
Regardless of which map you choose to use, understanding how each map works and both it’s strengths as well as it’s weaknesses will only make your decision easier. Ultimately the map you go with should be the one that best fits the needs of the scenario you find yourself dealing with.

All the maps together
plane put together.png



Here some handy sites to help you!
Online normal map generator and displacement map generator

I cannot use it, Chrome has no Web GL
It should work with Firefox, but i cannot confirm this.

I have used "Know the difference" as reference.
Last edited by Marcel2586 on Mon Apr 25, 2016 5:24 am, edited 8 times in total.
this would be funny if it weren't happening to me :shock:

User avatar
Kimberly58
Posts: 206
Joined: Sun Apr 27, 2014 12:52 am

Re: Bump map, normal map and displacement map

Postby Kimberly58 » Sat Apr 23, 2016 2:31 pm

Thank you for this! Bravo!!

User avatar
Marcel2586
Posts: 438
Joined: Sat Mar 05, 2016 7:42 am

Re: Bump map, normal map and displacement map

Postby Marcel2586 » Sat Apr 23, 2016 2:42 pm

Thank you Kimberly
Last edited by Marcel2586 on Sun Apr 24, 2016 5:39 am, edited 1 time in total.
this would be funny if it weren't happening to me :shock:

pciccone
Site Admin
Posts: 1801
Joined: Mon Feb 25, 2013 6:25 pm

Re: Bump map, normal map and displacement map

Postby pciccone » Sat Apr 23, 2016 6:16 pm

Fantastic tutorial Marcel. Thank you very much for taking the time to make it.
--
Paolo

User avatar
Marcel2586
Posts: 438
Joined: Sat Mar 05, 2016 7:42 am

Re: Bump map, normal map and displacement map

Postby Marcel2586 » Sun Apr 24, 2016 7:56 am

this would be funny if it weren't happening to me :shock:

pciccone
Site Admin
Posts: 1801
Joined: Mon Feb 25, 2013 6:25 pm

Re: Bump map, normal map and displacement map

Postby pciccone » Sun Apr 24, 2016 8:31 am

You don't need any green light from me, if you have anything ready, by all means, please oublish it. People are thirsty for knowledge :)
--
Paolo

User avatar
fuzzy70
Posts: 218
Joined: Mon Jul 13, 2015 9:38 pm

Re: Bump map, normal map and displacement map

Postby fuzzy70 » Sun Apr 24, 2016 11:26 am

Attachments
100subdistest.png
5subdistest.png
Windows 10 x64, Daz Studio 4.9 x64, Poser Pro 11 & whatever the current version of Reality is :lol:

User avatar
Marcel2586
Posts: 438
Joined: Sat Mar 05, 2016 7:42 am

Re: Bump map, normal map and displacement map

Postby Marcel2586 » Sun Apr 24, 2016 12:12 pm

Thank you for pointing this out. i formulated it wrong i will correct this. And i forgot to mention that the more segments the higher detail you get.
this would be funny if it weren't happening to me :shock:

User avatar
fuzzy70
Posts: 218
Joined: Mon Jul 13, 2015 9:38 pm

Re: Bump map, normal map and displacement map

Postby fuzzy70 » Sun Apr 24, 2016 12:20 pm

No problem Marcel, writing tutorials/tips it's very easy to make some errors, I often do & sometimes spend more time editing than making the thing in the 1st place lol.

Great tut though :)

Regards

Lee
Windows 10 x64, Daz Studio 4.9 x64, Poser Pro 11 & whatever the current version of Reality is :lol:

User avatar
Marcel2586
Posts: 438
Joined: Sat Mar 05, 2016 7:42 am

Re: Bump map, normal map and displacement map

Postby Marcel2586 » Mon Apr 25, 2016 5:21 am

this would be funny if it weren't happening to me :shock:


Return to “Tips, techniques, and recipes”

Who is online

Users browsing this forum: No registered users and 2 guests