Anisotropic surfaces?

TurnerTurner Posts: 114
edited December 1969 in Carrara Discussion

Hi all,

Could swear I saw something to do with rendering anisotropic surfaces (without using bitmaps) but I can't find it... maybe I was thinking of another program.

Any help appreciated.

thx
Andrew

Comments

  • 3DAGE3DAGE Posts: 3,311
    edited December 1969

    Hi Turner :)

    In the shaders editor,. at the top of the list,. click the "multichannel" blue button,. and select Lighting models / Anisotropic model.
    then you can change the direction if you want.

    Hope it helps :)

  • TurnerTurner Posts: 114
    edited December 1969

    Thanks! Found it!

    That said.. sure could use a tutorial.

    Basically, I'm trying to create a flat piece of metal with a linear brushed finish.

    Any ideas?

    thx
    Andrew

  • evilproducerevilproducer Posts: 9,040
    edited December 1969

    Look at the included content. There's some brushed metal shaders. You could open them and up and see how they're constructed. If there's some effect you like see how it was done. If there's an effect you don't like, it helps to look to see what to avoid.

  • TurnerTurner Posts: 114
    edited December 1969

    Look at the included content. There's some brushed metal shaders. You could open them and up and see how they're constructed. If there's some effect you like see how it was done. If there's an effect you don't like, it helps to look to see what to avoid.
    '

    Yep... done that. Couldn't really replicate what I am looking for.

    Here's an example of the surface texture (lower half of the object, subtle lines from extrusion mold)

    http://imagethumbnails.milo.com/024/833/442/trimmed/24833890_26000442_trimmed.jpg

    thanks,
    Andrew

  • evilproducerevilproducer Posts: 9,040
    edited December 1969

    You may be able to use some of Carrara's other shader functions for that. I might experiment to see what I get.

  • evilproducerevilproducer Posts: 9,040
    edited December 1969

    I played around a bit, and if you want a rougher looking extrusion/tool marks it'll require someone more skilled than myself. I did get a decent (in my opinion) look, but it looks a little too uniform and clean compared to your reference photo. You might get a rougher look by layering more procedural functions on top of each other. The other possibility is to use an image map.


    Here's a sample image and the shader settings. I copied the Highlight's settings and pasted them into the bump channel, so they're identical.

    Picture_4.png
    714 x 493 - 88K
    Picture_3.png
    708 x 442 - 78K
    Picture_2.png
    712 x 332 - 73K
    Picture_1.png
    717 x 582 - 129K
    anistropic.png
    1024 x 768 - 301K
  • evilproducerevilproducer Posts: 9,040
    edited December 1969

    ...And what the mixer's blender was set at:

    Picture_5.png
    719 x 578 - 93K
  • TurnerTurner Posts: 114
    edited December 1969

    Thanks - that looks more like the top to me; the real effect I'm going for is a slightly irregular, very shallowly "scraped" surface (what happens when the metal comes through the extruder) with anisotropy, if that's possible.

    The included settings work well for curved surfaces, but I haven't found how to create the same effect on a flat surface.

    cheers
    Andrew

  • evilproducerevilproducer Posts: 9,040
    edited December 1969

    You might be able to adjust the regular clean look by playing with noise in the bump channel. Otherwise, an image map may be the way to go.

  • TurnerTurner Posts: 114
    edited December 1969

    Thanks -

    I'll have to experiment, as I need it to look realistic when animated, too... I'm sure there's a way to do it, just not sure what way that is yet! :)

  • cdordonicdordoni Posts: 583
    edited December 1969

    Veloute (inagoni) has procedural noise that you could stretch along an axis to get that kind of brushed effect. I believe Enhance:C (DCG) can do this as well. I think you can also add a procedural bump effect as well in both Veloute and Enhance:C

    While its not exactly the same as anisotropic, it might be close enough.

  • 3DAGE3DAGE Posts: 3,311
    edited December 1969

    Actually most of Carrara's built in patterns or noises have a "Transform" tab where you can adjust the scaling on whichever axis you need.

    I was messing around with this, and made a shader which uses fractal noise, cellular and the scan-lines pattern, mixed with a gradient so that you can control where the scanlines start and stop,

    it's a bit rough,. and it's not a good example of lighting, ...or modelling :) but it's the shader I'm playing with..so it'll do.

    I think this shader is still kind of rough, and perhaps a bit too shiny reflective, but workable.

    test render.

    brushed_3.jpg
    800 x 600 - 52K
  • evilproducerevilproducer Posts: 9,040
    edited December 1969

    Looks really good Andy. I knew that it could be done! I just didn't have time to futz with it as much as I would have liked.

  • 3DAGE3DAGE Posts: 3,311
    edited December 1969

    HI Evil :)

    Thanks :

    I think the transform tab in the noises and patterns is an under used option, so it was good fun to play around with this over the weekend.

    Here's the scene with the model and shaders.

    https://dl.dropbox.com/u/7907045/extrusion1.car

    noise_scaling.jpg
    886 x 740 - 119K
    shadr_settings.jpg
    1000 x 672 - 128K
  • h1n0k4m1h1n0k4m1 Posts: 0
    edited December 1969

    i also used metal texture on the next image.
    i don´t have a link for the texture.
    but if you need just pm me ^^

    bullet.jpg
    1000 x 1000 - 591K
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