high frequency normal maps

caeleni

Hi guys

polycount is awesome,i already found many answers just browsing around
thanks to all the contributors



so i'm trying to have a basic knowledge of all the steps of a production pipeline
i'm currently going through the book of andrew gahan game art complete all in one.
well the part that handles the creation of an high frequency normal map isn't clear at all,he doesn't really explain this step
do i have to use the high pass filter?right way to sharp the details?correct way of hand edit the normal map?i got that the light information are stored in each channel in different way,but how do i work on each channel..

someone can point me in the right direction?

also i wanted to know how much the information,techiniques,workflows explained in this book are outdated now..i believe this book was written in 2009...

DireWolf

I don't know what the book covers. However, there has been quite a lot of new applications dealing with normal map popping up in recent years, so my bet is that the book is indeed outdated although still applicable.

As far as I know, today there are a couple ways to create normal maps. Painting per channel as you mentioned is probably only for fixing errors, not for generating.
1. Baking from high resolution mesh.
2. Convert from pictures. Can be hand painting black/white or photo.
3. Paint height map while application convert it to normal map in real time.
4. Paint normal maps directly.

1 is very popular, scupting high detail mesh in Zbrush or whatever, then use xNormal to bake normals down to low resolution mesh.

Ffor 2 you'd use application such as bitmap2material to convert pictures to normal. High pass can still be used in this case to remove light/shadow information from your image before conversion.

Here's some example of 3, using nDo2.
[ame]https://www.youtube.com/watch?v=xDZDWvTUz-c[/ame]


And here's an example of 4 in Substance painter. Go to 18:00 minute or so.
https://youtu.be/QhcatW6yxQQ?t=18m8s

caeleni

direwolf first of all,thank you!
i knew nDo2 but i never tried it,definitely worth a check

i know the baking from high poly to low poly,no problem with that
it's the whole question about painting a normal map using photoshop that i didn't fully get yet

that part of the book talks about creating a high frequency map for details that would be impossibile or absolutely time consuming to add manually,even with zbrush,like the grain of a wooden door
the next step would be combining high frewquency and low frequency normal map together with programs like crazybump

than for what i understood it's always better to paint the diffuse to get a better results in programs like crazybump in conversion from texture( for environmental texture maps)where you don't want/can't spend too much time..is this still right?

it's the part of what to do manually to enahance results in autogeneration for all the different types of maps(normal,height,speculr) that is not clear

AdvisableRobin

So, what you're talking about creating is a 'Detail Map', in almost all current gen engines there is a slot or node able to handle it. A detail map is just a tiling high frequency map. If you just combine the high and low frequency detail in the main normal map you'll often end up with some that is way to noisy and has no visual rest.

Now, back to your original question which I would like to clarify. You are asking about the process of auto generating other types of maps based on manual painting?

AlecMoody

FWIW I recently posted some information about this on art station:
Sculpting overview:
https://www.artstation.com/artwork/sculpting-micro-texture-tutorial

bake output process:
https://www.artstation.com/artwork/the-order-1886-grenade-baking-breakdown-micro-texture-handling


If you want to use tiling detail normals the best advice I can give is to by very careful about how you blend the two texel densities and detail scales. If They are too different, it will read really clearly as a detail map overlayed onto something blurry. Often it looks better to tile the detail map slightly fewer times, providing less ultimate resolution, in order to create better transition between the two detail scales.

AdvisableRobin

Oh wow, thanks for sharing Alec, that's really helpful actually.

caeleni

alec thank you
your work is impressive
your sculpting micro texture tutorial--->directly into my workflow notes


robin thanks,combining isn't the way,i figured it out
so a detail map is just a tiling high frequency map,but how do i create it?
in the book it doesn't explain this step,i can figure it out by myself but what is the correct way?

you helped me to clarify a bit the mess in my brain
it's the process of auto generating maps based on manual painting or enhance the result of map generations using dedicated programs by manual painting for things i cannot/don'want to sculpt,mostly starting from a simple texture like a photo,that i'm missing!

i think
practically what you said robin :thumbup:

caeleni

guys sorry to bother again but i don't get this part

if i want to hand edit the high frequency normal map i have to work on each color channel individually,the channel informations are stored in each channel in a different way

red is lit from left to right
green is lit from top to bottom
blue is depth


no idea how to hand edit each channel...gradients?

AlecMoody

What are you trying to do to your normal map? generally, hand editing like you are describing is a bad idea.

AdvisableRobin

I would look into using Substance Designer 5, it is very easy to create tillable textures using it. If you are absolutely set on using Photoshop, then any hand editing you do has to be done to the height map, which you can then convert to a normal map using any number of available plugins or programs.

What exactly are you trying to edit in the normal map? Can you post images?

caeleni

what i was following and trying to do is exactly this

http://nedrilad.com/Tutorial/topic-116/Game-Art-Complete-107.html

sure robin but before using programs that automatize a process i always try to know exactly how it works and if i can be able to do it manually

i'm going to try ndo and substance designer but do they create and are they good in creating all the kind of maps(normal,ao,specular...)or they specialize in one type?

AdvisableRobin

You can create any type of map, PBR and old-school system. Check out the substance thread here to see some examples of materials created using only substance.

pixelquaternion

Hi there,

I was experimenting a lot with that last week and my conclusion are very simple, editing each Chanel with level in photoshop and then normalize the result with the xnormal plugin for photoshop or the nvidia plugin.

It gave me amazing result specially for stone wall apply on a flat plane, just make sure to not over do it in the level and you will see the NM pop off really well.

Regards Peter

AdvisableRobin

As long as you Normalize after you edit, it technically should be correct. But thats like chopping wood with a hammer when you have an entire array of axes available to you. There are easier ways to do it.

caeleni

thanks guys

i got a decent result with the high frequency map
and i think i'm in love with substance designer now

Eric Chadwick

Take a look at the Viking Village demo in Unity, they did a nice job with detail maps for their wood structures. You can dl it and examine in detail how it was done.

http://blogs.unity3d.com/2015/02/18/working-with-physically-based-shading-a-practical-approach/