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Normal Maps? Coloured or Blue? Methods of simulating wrinkles in Clothes? 
Posted: 19 July 2012 10:27 PM   [ Ignore ]
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Dah hi wink silly question time.


I guess that Carrara takes normal maps tjhat are blue.
I ask because
Inagoni Baker I notice puts out also coloured ones. Are these just related to z brush?

Only asking because, I’m tryingto use normal maps to simulate clothing wrinkles and really can’t tell the difference…. :(
unless I jack the value up very high.

Any methods for simulating wrinkles in clothes without going the displacement route?

Eg could you use displacment,  export the mesh with the dispplacement as an object with added geometry ?
then err , umm,
The idea would be to use the displacement as a normal map generator I guess.

Not for animation ,just stills.

thanks for your advice

regards from oz smile

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Posted: 20 July 2012 03:46 AM   [ Ignore ]   [ # 1 ]
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HI Head Wax smile

Typically, a normal map should be a mix of red and blue,  in the same way that a Bump or displacement map is a mix of black and white.
See example Normal and Bump / displacement maps
 
The baker normal maps “for Z-brush” should work fine from a model, but again, Filterforge or several other programs can be used to generate a normal map without the modelling steps.

Hope it helps smile

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Posted: 20 July 2012 04:28 AM   [ Ignore ]   [ # 2 ]
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I’m a big believer in “there’s no wrinkles like real wrinkles”. If you just want some type of map that adds foldy-ness to the mesh, then IMO you’ll get something that looks unlike real wrinkles.


I’m not sure what type of object you want to add wrinkles to, but I would tend to generate real folds based on the parameters of the particular cloth you’re modelling. It’s extremely difficult, IMO, to hand draw an image map to generate wrinkles appropriate for the cloth you’re simulating.


So I’d first look at taking the mesh into a cloth sim (Poser, Blender, Bullet, whatever) and drape the cloth so that you get appropriate wrinkles, then export the result either as a morph target, or as a replacement object that you can re-rig, or whatever way is appropriate to what you’re doing.


I also recall there was a lot of discussion a while back about normal maps in Carrara, and I think bottom line they aren’t really any better than bump maps. Unless you’re talking about displacement maps, not normal maps.

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Posted: 20 July 2012 09:40 AM   [ Ignore ]   [ # 3 ]
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This is a “second skin” body suit on V3, using normal maps included with a bodysuit texture I bought at Rendo. The wrinkles and seams are from the normal maps (there are issues, it was converted from a texture for V4). the vinyl surface texture is procedural bump in Carrara, so I am combining bump and normal map.

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Posted: 20 July 2012 10:10 AM   [ Ignore ]   [ # 4 ]
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Part of the problem is that normal maps don’t really show “height” the way a bumpmap does, so cranking up the values on your wrinkles isn’t making it look more wrinkled… (it is making the effect more pronounced, but not really adding the illusion of physical height…


Normal maps show “slope”.... The light blue color is essentially flat. The other colors tilt the slope in various directions based on a gradient light to dark. It looks like colored lights are off to the sides casting shadows, and that is more or less what normal maps are…


Here’s a tutorial where someone is making normal maps from actual objects using side-lighting and color correction in photoshop: http://zarria.net/nrmphoto/nrmphoto.html For me this makes normal maps easier to understand. One slope is brighter, the opposite slope is in shadow. The brighter and darker the colors the steeper the slope….


What you probably need is a wrinkle normal map with sharper gradients. With some experimentation you might be able to take your normal map into photoshop and play with the levels in each channel to see what kind of effects you get. Essentially (I think) you want higher contrast in the green and red channels, but I have not tried this myself, so that is just my best guess….

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Posted: 20 July 2012 02:50 PM   [ Ignore ]   [ # 5 ]
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thanks so much for the quick replies!
unfortunately have been called out of town
will reply properly tomorrow
appreciate everyone’s sharing their knowledge
I’m glad I asked!
cheers

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Posted: 20 July 2012 07:16 PM   [ Ignore ]   [ # 6 ]
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I like the old fashion way in carrara! Texture map done in Photoshop. then Grayscale it put in BUMP and wala! I watched a tutorial on youtube about was great! Using the SMUDGE tool to drag out Black and white images! Its been working out so great I have had to turn DOWN the value…

See this


Here are some samples..

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Posted: 20 July 2012 07:20 PM   [ Ignore ]   [ # 7 ]
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Here is my bump map for the SHIRT of the pilot!

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Posted: 21 July 2012 03:00 PM   [ Ignore ]   [ # 8 ]
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3dage wrote

HI Head Wax

Typically, a normal map should be a mix of red and blue,  in the same way that a Bump or displacement map is a mix of black and white.
See example Normal and Bump / displacement maps
 
The baker normal maps “for Z-brush” should work fine from a model, but again, Filterforge or several other programs can be used to generate a normal map without the modelling steps.

Hope it helps

Thanks Andy, yes it does help. I have Nvidia plugin for phtoshop and another program and both generate blue bump maps. It wasn’t till I played with Baker that I saw it generates both blue and multicoloured maps. From memory it was rainbow coloured though. (That computer is crashed so I can’t post he map :( )

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Posted: 21 July 2012 03:05 PM   [ Ignore ]   [ # 9 ]
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JoeMamma2000 - 20 July 2012 04:28 AM

I’m a big believer in “there’s no wrinkles like real wrinkles”. If you just want some type of map that adds foldy-ness to the mesh, then IMO you’ll get something that looks unlike real wrinkles.


I’m not sure what type of object you want to add wrinkles to, but I would tend to generate real folds based on the parameters of the particular cloth you’re modelling. It’s extremely difficult, IMO, to hand draw an image map to generate wrinkles appropriate for the cloth you’re simulating.


So I’d first look at taking the mesh into a cloth sim (Poser, Blender, Bullet, whatever) and drape the cloth so that you get appropriate wrinkles, then export the result either as a morph target, or as a replacement object that you can re-rig, or whatever way is appropriate to what you’re doing.


I also recall there was a lot of discussion a while back about normal maps in Carrara, and I think bottom line they aren’t really any better than bump maps. Unless you’re talking about displacement maps, not normal maps.

JoeMamma thanks I wasn’t aware of the normal map discussion. It certainly aligns with what Iv’e found so far in that case.Which is why I asked the question I guess. And yes you are right there’s no wrinkles like real wrinkles I only got to look in the mirror for that to be confirmed ....

For use? I am wrinlking some shirts etc as my critique group has flagged a lack of wrinkles in my illustrations.
What you suggest in draping the cloth in Poser at al is good idea but I will be probably doing many images and it would be impractical to use morphtargets. The only practical way is to draw them either in post or on the texture map before rendering

Thanks for your suggestion and headsup onthe other thread

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Posted: 21 July 2012 03:10 PM   [ Ignore ]   [ # 10 ]
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Holly wrote

Part of the problem is that normal maps don’t really show “height” the way a bumpmap does, so cranking up the values on your wrinkles isn’t making it look more wrinkled… (it is making the effect more pronounced, but not really adding the illusion of physical height…


Normal maps show “slope”.... The light blue color is essentially flat. The other colors tilt the slope in various directions based on a gradient light to dark. It looks like colored lights are off to the sides casting shadows, and that is more or less what normal maps are…


Here’s a tutorial where someone is making normal maps from actual objects using side-lighting and color correction in photoshop: http://zarria.net/nrmphoto/nrmphoto.html For me this makes normal maps easier to understand. One slope is brighter, the opposite slope is in shadow. The brighter and darker the colors the steeper the slope….


What you probably need is a wrinkle normal map with sharper gradients. With some experimentation you might be able to take your normal map into photoshop and play with the levels in each channel to see what kind of effects you get. Essentially (I think) you want higher contrast in the green and red channels, but I have not tried this myself, so that is just my best guess….


Thnaks HollyWetcircuit. smile It certainly is a second skin smile
To combine the normal map and the bump map in the shader room did you use an Operator? Eg Multiply, overlay etc?
Thanks for the link to th etut and theinfo on the colour channels.
I guess I should sit down and play with a UV eed mapped grey sphere and see what happenes with the different colours.

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Posted: 21 July 2012 03:13 PM   [ Ignore ]   [ # 11 ]
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Mr Chaos Wroteth:

I like the old fashion way in carrara! Texture map done in Photoshop. then Grayscale it put in BUMP and wala! I watched a tutorial on youtube about was great! Using the SMUDGE tool to drag out Black and white images! Its been working out so great I have had to turn DOWN the value…

See this

Smudge tool? How cool is that? The wrinkles look very good Richard.
Thanks fo rthat suggestion.
It is a tool I rarely use in post work so I forget it exists.
Much obliged for those examples.       
I think I will go and fire up photo shop .... wink

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Posted: 21 July 2012 03:16 PM   [ Ignore ]   [ # 12 ]
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One more question… In Carrara 8 pro in the render room, I can render photorealistic, non photorealistic etc,
But I can also render a normal map.
I see it renders in blue though.
I was wondering if it came with Carrrara originally or Baker installed it?
Can’t remember ans as there is no manual I can’t look it up…

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