modeling chainmail-type curtain

[wesware]

I'm sure mograph would be up to the task.
But the rendertimes....yeeeesh.

Although, perhaps you could use a hair shader to look like metal?... clone a slew of splines onto a poly curtain... then use hair to render the splines?

Might be more render and editor friendly.

[wesware]

You could also just do a bitmap alpha... with a bump.
Probably couldn't get too close to it though.

[LucentDreams]

Tangent normal map, of a small tile of area that sets to tile should be highly effect and you should be able to get fairly close.

[wesware]

Tangent normal map, of a small tile of area that sets to tile should be highly effect and you should be able to get fairly close.

Gah! Yes, the normal map... forgot!
I did a lighting test using CrazyBump to produce a Nmap from a photo of a cinderblock.
It's really amazing, the extra umph you get using a normal map.

Good call.

[nycL45]

I am glad normal maps was raised because I was searching for info on how to use them in C4D. So, where or in what channel would the normal map be dropped?

[AAAron]

I am glad normal maps was raised because I was searching for info on how to use them in C4D. So, where or in what channel would the normal map be dropped?


It would be the normal channel ;)

[nycL45]

It would be the normal channel ;)

It is outrageous that Maxon would hide the normal channel out in the open, in plain sight! No wonder I could not find it. Where is the consideration! Yeesh! Uh, um, yeah, thanks AAAron.


...he quietly shuffles away, head dropped, mumbling to himself – totally embarrassed.

[sketchbook]

hmm.

i trossed a chainmail tile into the normal map and all i get is a black and white bitmapped looking result.

time to read the manual.

[sketchbook]

ahha. can't use black/white bump looking textures in the normal map.

[LucentDreams]

your going to want to model a small section of chainmail, probably with mograph if you have it. put it in the center of the world and make sure its along the XY plane.

Then setup 6 lights on one each side of the object almost like the 6 faces of a cube.

so you should have two lights on Z, Two on X, and two on Y. The Top Y light should be set to green 50% brightness, the bottom to Green -50% brightness. The the Right X should be Red 50% brightness, the left, Red -50% brightness, and finally the one behind the object is blue -50% brightness and the one in front of the object is Blue 50% brightness.

Render this at 16 bit and you have yourself a normal map. make sure it can tile though.


in case my tutorial was too simplified here is a more indepth one http://www.bencloward.com/tutorials_normal_maps11.shtml

[etype]

Here is a polygon chainmail curtain. You'll have to excuse the wierdness - after making it for you I attached a windgenerator (now disabled) and various displacement maps and animation to experiment with the effect. I have went back to the original as far as possible before uploading.
How was it made ? - pretty elementary - an extruded cylinder duplicated along a spline. You can definetly refine this - but as is, is what you need perhaps, to get started.

You can use this technique to get an excellent normal map.

http://forums.cgsociety.org/attachment.php?attachmentid=&stc=1

[Per-Anders]

I find it much easier to simply render a normals pass in Cinema (Material Normal in multipass tab), then use that (render looking along -z). Of course you can also make a normals material (using falloffs in the luminance channel).

[LucentDreams]

the falloff will work well too. The material normal pass isn't good because its an object normal map not a tangent, so it wont' deform well.

[Per-Anders]

No it's fine, so long as you look down in -z, you are effectively getting a tangent normal map in that instance.

[LucentDreams]

similar but backwards and not quite right.

Lights
http://kaithestuffguy.com/cinemajunk/light.jpg

-Z
http://kaithestuffguy.com/cinemajunk/backz.jpg

+Z
http://kaithestuffguy.com/cinemajunk/frontz.jpg


The lights normal map will produce a much better result.

[3DBond]

Not a modeling solution but you could look up Aurety's Armor shader from the Maxon 2005 Fabric challenge. It's ridiculously good. Not sure what kind of usage rights there are on it or even how to find it easily again.

[sketchbook]

cool. i do have those fabrics somewhere. i will look that up.

cheers.

[Per-Anders]

similar but backwards and not quite right.


The lights normal map will produce a much better result.

Not sure what you mean not quite right, it's correct (and there's a switch in the normal channel of cinema to flip any channel, in this case X to match your light setup).

The lights is actually a worse result for two reasons, firstly it's not producing a correctly normalisd value (i.e. where each vector is normalised, i.e. if you added up r+g+b the result would be 1, the falloff shader method also suffers there because it's also merely additive), secondly both the falloff shader and the simple normal channel are actually more accurate, for the simple reason that with a light it's limited to casting on the side of the polygon that faces it, now that seems OK at first till you realise that normals are centralised to 50%, so e.g. at 90 degrees to +X the R channel is (before normalisation) at 50% not at 0%, but with a light that's it's terminator, i.e. it reaches 0. In fact with the normal at 180 degrees i.e. in the -x direction R is at 0. With lights you then have to work from the 50% grey setup and use subtractive values to get around this which is massively complex for such a simple thing and still results in an innacurate result (especially when you take into account the illumination model itself and effects such as lights contrast). The lights method is very clever, but overly complex and doesn't tend to produce very accurate results.

There used to be one other method available and that was the NLinShader by Frank Plohmann, sadly the plugin and website has gone AWOL, however here is the tutorial that went with it http://planetpixelemporium.com/tutorialpages/normal2.html However it basically works the same way as using the falloffs (i.e. you make a layers shader in your luminance channel and use three falloffs in it, one red, one green, one blue, set to camera space and the appropriate directions).

I've attached the falloff material so you can pull it apart, it's very simple and reusable in any scene and with any camera position. Just load it in through your material editor and apply to whatever, you can bung a bump channel in it too if you want, or even just grab the layers shader probably and store it in your browser so you can plug it into any old material of your choice, just remember that it goes in the luminance channel.

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